FR2677022A1 - DERIVATIVES OF VITAMIN D COMPRISING AN EPOXY GROUP ON THE LATERAL CHAIN. - Google Patents

Abstract

Compounds derived from vitamin D or one of its analogs having, in particular, a lateral chain grafted in position 17 on the D ring of vitamin D. Said compounds are characterized in that they include an epoxide group grafted on said lateral chain, the epoxide group being separated in position 17 by a linear chain of at least two atoms. The invention also concerns a process for the preparation of said compounds and their use as drugs.

Description

 The present invention relates to novel vitamin D derivatives, a process for preparing these derivatives and their therapeutic applications.

 Vitamin D is one of the most important biological regulators of mineral and bone calcium and phosphorus metabolism. In combination with two peptide hormones, calcitonin and parathyroid hormone (PTH), vitamin D is responsible for the control and maintenance of mineral and bone homeostasis.

 Vitamin D is considered today as a steroid hormone in its own right, and more precisely as a prohormone which, after successive metabolism among others in the liver and the kidneys, gives rise to a biologically active compound, the alpha, 25- Dihydroxy-vitamin D. This last hormone is the major element of a complex endocrine system. It plays a role, not only in phospho-calcium metabolism by acting on the classical target tissues (intestine, bone, kidneys and parathyroid), but also in the control of important cellular processes (growth, differentiation and various biological functions) with level of a large number of other normal or cancerous tissues [1-3].

 The general term vitamin D applies to both vitamin D2 (ergocalciferol) of plant origin and vitamin D3 (cholecalciferol) naturally present in animals. In humans, these two forms of vitamin D have a very similar biological role. It is therefore not very significant to consider them separately. Vitamins D are defined as seco-steroids, ie molecules characterized chemically by a steroid ring with 4 rings and ring B is open at C-9 and C-10.

 In the present application, therefore, vitamin D is understood to mean both vitamin D3 and vitamin D2.

In humans, the main source of vitamin D is endogenous and in the form of vitamin D3. Vitamin D3 is produced from 7-dehydrocholesterol, a precursor synthesized at the trepidermal level, under the action of ultraviolet light
solar. Insufficient solar exposure can be offset by a
exogenous supply of vitamins D2 and D3.

STRUCTURE OF VITAMIN D

Vitamin D3 or Cholecalciferol Vitamin D2
Vitamin D undergoes a first hydroxylation in position 25, the first metabolic transformation, generating 25-hydroxyvitamin D (hereinafter 25- (OH) D), one of the main forms of vitamin
Circulating D. This metabolite has a high affinity for a protein carrier protein, called DBP ("vitamin D binding protein"), but a low affinity for the intracellular receptor vitamin D. After hydroxylation at the 1 alpha position at the renal level, the 25- -hydroxyvitamin
D is converted to 1 alpha, 25-dihydroxy vitamin D, or abbreviated 1 alpha, 25- (OH) 2D3, which is the biologically active form of vitamin D.

This metabolite has a low affinity for DBP and a high affinity for the intracellular receptor. Its blood level is regulated within very narrow limits.

 The metabolism of vitamin D produces a whole series of other metabolites whose physiological role, if any, is still poorly defined. The alpha-hydroxylase, the enzyme responsible for the activation of 25- (OH) D, is also present in the placenta, the intestine, the breast, the epidermis (keratinocytes), the bone cells (embryonic and normal), some hematopoietic cells (macrophages and monocytes), as well as granulomatous tissues during granulomatous diseases, such as sarcoidosis).

 The primary pharmacological role of vitamin D is the regulation of calcium and phosphorus metabolism in classical target tissues. It stimulates the intestinal and renal absorption of calcium and phosphorus, the bone mobilization of these same minerals (resorbtion or mineralization), while it regulates the secretion of the parathyroid hormone controlling renal 1 alpha-hydroxylase. Thus, excessive production of vitamin D (accompanied by hypercalcemia, hypercalciuria, and their consequences) is observed in cases of hyperparathyroidism.

The vitamin D receptor has been identified in many normal tissues, such as skin, muscles, pancreas, brain, thyroid, placenta, colon, bone (osteoblasts), thymus, and cells. of the immune system (monocytes, macrophages, lymphocytes
B and T activated). Many cancer cells of all origins have vitamin D receptors; mention may be made of leukemic cells of monocytic (myeloid) or lymphocytic origin (lymphoma), melanomas and carcinomas of the colon, bone and breast.In these tissues, vitamin D plays an important role in the cell proliferation and differentiation, and in the regulation and modulation of the immune system in the same way as estrogens and glucocorticoids, and more recently vitamin A. It regulates the growth and differentiation of normal cells (embryogenesis) and cancerous (arrest of proliferation and / or induction of cell differentiation).

It also behaves as an immunomodulatory substance (eg stimulation of non-specific immunity by monocytes, inhibition of specific lymphocyte immunity).

 Vitamin D plays a fundamental role in many natural biological processes. Any anomaly in the contribution or the regulation of the metabolism of vitamin D results in more or less important pathologies. Currently, the pathologies associated with vitamin D are classified as deficiencies or in excess of vitamin D.

Deficiencies or deficiencies of vitamin D are due to insufficient sunlight associated with a deficit of exogenous intake by food or during malabsorbsion syndrome, abnormal metabolism of vitamin D, or when the tissues are resistant to its action . Metabolic abnormalities are associated with disorders related to (a) the production of 25- (OH) D (liver diseases, prolonged use
anticonvulsants or corticosteroids) (b) to the production of 1 alpha, 25- (OH) 2D3, by absence or deficiency of
hydroxylation in position 1 alpha (case of vitamin-resistant rickets
type I), or (c) its biological action, by the absence or a deficiency of the receptors
Vitamin D (case of Vitamin Resistant Rickets)
type II).

Vitamin-resistant rickets is hereditary. The metabolism of vitamin D can also be disrupted during various pathologies, and in particular, hypophosphatemic familial rickets (renal tubular deficiency in phosphate transport), chronic renal failure (renal osteodystrophy), diabetes mellitus (increased the incidence of osteopenia, osteoporosis and fractures), hypoparathyroidism and certain cancers (multiple myeloma), or by pharmacological interactions, particularly with antiepileptic drugs and corticosteroids.

 The clinical manifestations of these vitamin D deficiencies appear most clearly in the bone: rickets of the child and osteomalacia of the adult, and perhaps participation in the phenomena of osteoporosis. There are other more discreet associated disorders, such as immune deficiency in children with rickets, a higher incidence of certain cancers, including colon, associated with a deficiency of calcium and vitamin D, or vascular and endocrine disorders.

 Excess vitamin D occurs mainly during vitamin D intoxication or during ectopic production of active metabolites, for example during ganulomatous diseases (sarcoidosis). It is the same in hyperparathyroidism, stimulating the excessive production of 1 alpha25- (OH) 2D3.

 The usual deficiencies in vitamin D are easily corrected by the exogenous supply of vitamin D. The active derivatives of vitamin D and in particular 1 alpha, 25- (OH) 2D3, must be administered if the metabolism is abnormal, especially in kidney failure. These have a very narrow therapeutic index, so that vitamin intoxications are common during their administration. On the other hand, 1 alpha, 25 (OH) 2D3 has a short half-life which often justifies two daily doses. In addition, prolonged treatments are accompanied by hypercalcemia, hypercalciuria, and their consequences, especially in the liver and kidneys. The search for derivatives with a different pharmacokinetic profile and a more favorable therapeutic index therefore remains relevant.

 The particular regulatory role of vitamin D, especially in terms of cell proliferation and differentiation, can be used to control certain pathologies that are not directly related to a vitamin D metabolism disorder.

 The development of new vitamin D analogs opens perspectives in the field of recognized applications, such as secondary hyperparathyroidism [4-6], skin pathologies, including psoriasis [7-12], dyskeratosis and acne, osteoporosis, including postmenopausal osteoporosis, senile or due to an excess of corticosteroids [13,14], or potential applications in endocrinology, such as the regulation of insulin secretion by the pancreas, in immunology, such as autoimmune diseases or immunoregulation, for example during organ transplants [15,16], or in oncology, such as leukemia, lymphomas, myelodysplastic syndromes [17-19].

 The biomedical potential of a vitamin D analog will depend essentially on the possibility of distinguishing or dissociating different forms of biological activities, in particular between the calcemic effect and the cellular effect.

 An object of the present invention is to make certain modifications to the side chain of vitamin D so as to obtain such a distinction, in particular by maintaining a biological activity similar to or even greater than that of the natural hormone, while reducing the calcemic effect, especially on bone tissue.

 1 alpha, 25- (OH) 2D3 and its precursor, 1 alpha-OH-D3 are used in renal failure and osteoporosis [13,14]. Calcipotriol, or 22-ene-24-cyclopropyl-1 alpha, 24- (OH) 2D3 from Leo Pharmaceutica [11,12], has also been proposed for the treatment of psoriasis.

Other derivatives are under research and development. Their therapeutic use underscores the growing interest in vitamin D analogs in human medicine.

 Although the results obtained to date with the first vitamin D synthesis analogs mentioned above are interesting and encouraging, their therapeutic efficacy is still limited.

 An object of the present invention is to provide novel vitamin D analogs for improving the biological selectivity and therapeutic index of vitamin D analogues.

 More particularly, an object of the present invention is to provide novel analogues for modulating or dissociating the different biological activities of vitamin D on the target cells and, for example, providing active compounds on cell differentiation but not very active on the cell. phospho-calcium metabolism to increase the administrable doses and the therapeutic index for the therapeutic indication concerned.

dans laquelle - V représente un reste de la vitamine D ou d'un de ses analogues dont la
position 17 est vacante - X greffé en position 17 de V représente une chaîne hydrocarbonée,
notamment alkylée, de O à 15 atomes de carbone éventuellement
substituée ou modifiée, notamment pouvant comporter, en une ou
plusieurs positions, un ou des groupe(s)
hydroxyle, méthyle, éthyle, halogène, de préférence fluor,
ester, notamment un groupe RlCOO avec R1 qui représente un alkyle
ou alcoxy en C1 à C7 linéaire ou branché, saturé ou insaturé,
éventuellement substitué notamment par un ou des groupe(s) hydroxy
ou halogène de préférence fluor,
éther, notamment un groupe R1 -o avec R1 qui représente un alkyle
ou alcoxy en C1 à C7 linéaire ou branché, saturé ou insaturé,
éventuellement substitué par un ou des groupe(s) hydroxy ou halogène,
oxo sous forme cétonique,
. un cycle ou hétérocyle, notamment cycloalkyle saturé ou insaturé,
aromatique ou hétéroaromatique pouvant porter tous les groupes et
modifications mentionnés ci-dessus, et/ou - ladite chaîne X pouvant comporter à la place d'un ou plusieurs de ses atomes de carbone, un atome d'oxygène, d'azote ou de soufre, - ladite chaîne X pouvant être insaturée, avec une ou plusieurs double(s) ou triple(s) liaison(s) carbone-carbone, cette chaîne insaturée pouvant porter tous les groupes et modifications mentionnés ci-dessus, et - ladite chaîne et les différents groupes situés sur la chaîne pouvant adopter toutes les formes isomériques, - le groupe époxyde

The subject of the present invention is therefore derivatives of vitamin D or of one of its analogues, having a side chain grafted at position 17 on the D ring of vitamin D, said side chain comprising an epoxide group, in particular the compound answering the formula

in which - V represents a residue of vitamin D or one of its analogues whose
position 17 is vacant - X grafted in position 17 of V represents a hydrocarbon chain,
in particular alkyl, from 0 to 15 carbon atoms
substituted or modified, in particular may include, in one or
multiple positions, group (s)
hydroxyl, methyl, ethyl, halogen, preferably fluorine,
ester, especially a group RlCOO with R1 which represents an alkyl
or C1-C7 linear or branched, saturated or unsaturated alkoxy,
optionally substituted in particular with one or more hydroxyl group (s)
or halogen, preferably fluorine,
ether, especially a group R 1 -o with R 1 which represents an alkyl
or C1-C7 linear or branched, saturated or unsaturated alkoxy,
optionally substituted with one or more hydroxy or halogen groups,
oxo in keto form,
. a ring or heterocyl, in particular saturated or unsaturated cycloalkyl,
aromatic or heteroaromatic that may carry all the groups and
modifications mentioned above, and / or said chain X may comprise, in place of one or more of its carbon atoms, an oxygen, nitrogen or sulfur atom, said chain X possibly being unsaturated, with one or more double or triple carbon-carbon bonds, that unsaturated chain may carry all the groups and modifications mentioned above, and said chain and the different groups on the chain which may adopt all isomeric forms, - the epoxide group

can be grafted onto any one of the 15 carbon atoms of
X, in particular at its end, an epoxide group in which
R1, R2 and R3, which may be the same or different, represent
a hydrogen, a C1-C10 alkyl group, linear or branched,
saturated or unsaturated, possibly substituted with one or more
group (s) halogen, hydroxy, cycloalkyl, also possible
substituted with halogen or hydroxy groups
R1 and R2 can be part of the same cycle, such as carbocycle or
heterocycle, and in this case R3 has the same meaning as above.

. R2 and R3 can be part of the same cycle, such as carbocycle or
heterocycle, and in this case R1 has the same meaning as above
. the different isomeric forms at the level of the epoxide being
possible.

et dont la formule complète peut avoir des substitutions dans toutes les positions autre que la position 17 du cycle D.The term "vitamin D rest" or vitamin D (V) analogues is understood to mean a compound whose basic structural skeleton has the formula

and whose complete formula may have substitutions in all positions other than position 17 of cycle D.

 In particular, V may represent a residue - C-derivatized analogs which have been described by the applicant in EP 341158 - derivatives having a double bond between C16-C17 described in U.S.

199167 and EP 050325 - compounds with a heterocycle between C6 and C10 which have been described in EP 81793, EP 78704 - derivatives having various derivations C3 and C1 which have been described in WO 90/10620.

dans laquelle X, Rl à R3 ont les significations données ci-dessus et

représente une simple liaison ou une double liaison ; - A représente un hydrogène, un méthyle ou le groupe méthylène =CH2j - Y identique ou différent représente H, OH, un groupe ester, notamment
R1COO, ou éther, notamment R1O, avec R1 qui a la signification
donnée ci-dessus. The compounds according to the invention will most often meet the formula

in which X, R1 to R3 have the meanings given above and

represents a single bond or a double bond; - A represents a hydrogen, a methyl or the methylene group = CH2j - Y identical or different represents H, OH, an ester group, in particular
R1COO, or ether, especially R1O, with R1 which has the meaning
given above.

Among these, compounds in which X represents an alkyl chain of 0 to 6 carbon atoms, of which optionally a carbon atom is replaced by an oxygen atom, which may be optionally substituted, in particular by one or more group (s), are preferred.
methyl, hydroxyl, ether, especially a group RO, and / or unsaturated
with a double or triple carbon-carbon bond, the epoxy group being
grafted at the end of the alkyl chain X, R1, R2 and R3, which can be
identical or different, representing a hydrogen, a hydroxy, a
alkyl group, especially a methyl or ethyl or a hydroxyalkyl.

et notamment aux quatre formes isomériques pures ou en mélange

dans lesquelles Z représente une chaîne alkyle saturée ou insaturée de 0 à 3 atomes de carbone, éventuellement substituée ou modifiée comme mentionné pour X précédemment, en particulier substituée par un hydroxy, un alkyl, tel que méthyl ou éthyl, sur l'un ou plusieurs des atomes de carbone, et R1 à R3 et R1 ont les significations données ci-dessus, le groupe époxyde étant greffé à l'extrémité de 7.In particular, there may be mentioned compounds that respond to the
formula II

and in particular to the four pure or mixed isomeric forms

in which Z represents a saturated or unsaturated alkyl chain of 0 to 3 carbon atoms, optionally substituted or modified as mentioned for X above, in particular substituted by a hydroxy, an alkyl, such as methyl or ethyl, on one or more carbon atoms, and R1 to R3 and R1 have the meanings given above, the epoxide group being grafted at the end of 7.

Among these are the compounds according to formula IIa or IIb with
R1 R2 R3 Z
CH3 HH-CH2-CH2
CH3 HH-CH2-CHOH
H CH3 CH3 -CH2
HHH -C (CH3) 2
CH3 HH

 The compounds according to the invention can be prepared by methods known to those skilled in the art.

et du n-butyllithium, avec un composé dont le squelette structurel de base a la formule III

dans lesquels les fonctions réactives greffées sur les squelettes de III et IV sont éventuellement protégées et
X, R1, R2, R3, dont les fonctions réactives sont éventuellement protégées, ont les significations données précédemmment, puis l'on déprotège éventuellement lesdites fonctions réactives notamment de X, R1, R2, R3 et hydroxyle en positions 1 et 3.The subject of the present invention is also a method for preparing a compound according to the invention, characterized in that the anion obtained is reacted from a compound whose basic structural skeleton has formula IV

and n-butyllithium, with a compound whose basic structural skeleton has formula III

in which the reactive functions grafted on the backbones of III and IV are optionally protected and
X, R1, R2, R3, whose reactive functional groups are optionally protected, have the meanings given above, and then the said reactive functions, in particular X, R1, R2, R3 and hydroxyl in positions 1 and 3, are optionally deprotected.

 This type of coupling is described in the literature [28].

 Similarly, the synthesis of derivatives of formula IV has been described [29].

In particular, the derivatives of formula Ib in which Y represents OH or OR1 can be obtained from

 The compound of structure III 'can be obtained by several routes, including those shown in scheme la below.

A first sequence comprises the following steps: a) reacting a compound whose basic structural skeleton has
formula VI in which
Tos is the tosylate group,
R2 is hydrogen or a protecting group for alcohol, and
X has the meaning given above with possibly
reactive groups, especially hydroxy in protected form, and
W and Z 'represent hydrocarbon chains which are parts
of X, such that -X represents -W-Z ', the string X being
constituted by the chains W and Z 'assembled to one of their
ends, W and Z ', thus having given meanings for X,
in particular Z 'may represent Z, including where appropriate groups
reagents, such as hydroxy, are protected,
with an organometallic derivative of formula VII in which Met is the
lithium or halomagnesium, b) then the olefin thus obtained is epoxidized, and c) after possible deprotection of the derivative whose structural skeleton of
Based on formula VIII, the hydroxy function is oxidized to a ketone.

A second sequence comprises the following steps: a) reacting the backbone compound VI with an organomeric derivative
of formula IX, followed by hydrolysis which releases the function
ketonic, b) which is then reacted with sulphurized ylides (sulfurylides), and c) after optional deprotection of derivative VIII, oxidized as above.

It is also possible to use one or the other of the following sequences, in which an organometallic derivative of formula X is reacted with tosylate XI or XII and then proceed to the respective epoxidations as described. previously. This latter route will be advantageous when W (and hence X) is a hydrocarbon chain in which a carbon atom is replaced by oxygen, sulfur or nitrogen. In this case the organometallic derivative X will preferably be prepared from Xa, where the labeled hydrogen H is bonded to oxygen, sulfur or nitrogen, by deprotonation. Otherwise X can be prepared from a halogenated derivative
Xb by transmetallation.

It should be noted that instead of a tosylate in the derivatives described above (VI, XI and XII) another leaving group, for example iodide, can be used.

<Tb>

<SEP> R, <SEP> R.
<Tb>

peuvent être greffés sur toute position de la chaîne Z', notamment à son extrémité. <SEP> t
<tb><SEP> gRz <SEP> Yg <SEP> R2
<tb><SEP> QaO <SEP>
<tb><SEP> VIII <SEP> III
<tb><SEP> R, <SEP> R1 <SEP> R,
<tb><SEP> A (<SEP> z '
<tb><SEP> R <SEP> R <SEP> TosO <SEP> R2
<tb><SEP> R1 <SEP> VII <SEP> Ri <SEP> Xl
<tb><SEP> W, Mlt
<tb> A <SEP> Z '; O <SEP> Rt <SEP> 4
<tb><SEP> A1
<tb><SEP> ~~ TO <SEP> È <SEP> TO
<tb><SEP> 51s
<Tb>
In VII, IX, XI and XII, the groups

can be grafted on any position of the chain Z ', especially at its end.

Different alternative ways of preparing the compounds will appear in the light of the examples which will follow
The present invention also relates to the use as a medicament of compounds according to the invention.

 The vitamin D analogs according to the invention, characterized by the presence of an epoxide function at the level of the side chain, constitute the first group of modifications of this type made to vitamin D. The epoxide function advantageously substitutes the hydroxyl group characteristic of the active form of vitamin D, and located in position 25. Indeed, until the present invention, all the biologically active analogs of vitamin D had at least one hydroxyl function in the side chain, especially in position 25 It has been found according to the present invention that the epoxide function located on the side chain of vitamin D makes it possible to obtain a biologically active analogue without the obligatory presence of a hydroxyl function at the level of the side chain.Furthermore, the function epoxy gives particularly interesting biological properties to the corresponding products, which do not have this functio not. It appears, in fact, that the epoxy group in itself confers a biological activity and that this activity is different from that conferred by the hydroxy group.

 On the one hand, the epoxide function confers on 1-hydroxyvitamin D, an inactive metabolite of vitamin D, biological activities that are specific and characteristic of the active form, 1 alpha, 25- (OH) 2D3. For example, the derivative 1 alpha hydroxy 25,26-epoxy-1-vitamin D3 (compound 24) increases by more than 100 times the capacity of 1 alpha-OHD3 to differentiate human leukemic cells (HL-60).

 On the other hand, the epoxide function confers a dissociated biological property with respect to the usual vitamin D analogues having a hydroxyl function at the side-chain position.

 At the level of differentiation-like cell properties, epoxide analogues generally behave as the active metabolite of vitamin D. They are also active to significantly more active than l-alpha, 25- (OH) 2D3.

Mention may in particular be made of the differentiation of human leukemic cells and epidermal cells (human keratinocytes) as well as the anti-proliferative effect on tumor cells, for example MCF-7.

 With regard to phospho-calcium metabolism, the calcemic effect of the analogues is considerably reduced (marginal activity) or even non-existent in the rickets chicken model. They are also much less able to stimulate the secretion of osteocalins by human osteoblastic cells in culture.

 This reduction in hypercalcemic side effects, observed in the case of epoxy analogues, does not prevent the effectiveness of the compounds in the context of osteoporosis. Indeed, the therapeutic effect in these circumstances - independent of the calcemic effect then results from the effect of differentiation on the bone type cells.

 Thus, the epoxide derivation can well dissociate the calcemic effect of other forms of biological activities. For example, the epoxy analogues and in particular the derivative 26a: (245,25R) -1-alpha-dihydroxy-25,26-epoxy, Vitamin D3 are capable of stimulating the differentiation of leukemic or epidermal cells without, however, inducing a calcemic effect. The significant reduction in calcemic effect gives these analogs certain advantages over vitamin D or its active metabolite, in particular to increase the concentration of compound that can be administered without influencing phosphocalcic metabolism, and thereby to increase the therapeutic index in many applications.

 The present invention therefore also relates to the application of the compounds according to the invention as a medicament.

The present invention therefore more precisely relates to the use of this medicament, in particular for the treatment and / or prophylaxis of skin pathologies, inter alia psoriasis, dyskeratosis,
acne, alopecia and aging of the skin, including the effect of
solar and light radiation - secondary hyperparathyroidism - cancers including leukemias, lymphomas, syndromes, syndromes
myelodysplastic, melanoma, breast, lung or colon cancers
and their metastases - autoimmune diseases including endoscinopathies such as
diabetes "mellitus"; neurological pathologies, such as multiple sclerosis
plaque and systemic diseases, such as lupus erythematosus,
glomerulonephritis - inflammatory processes, such as rheumatoid arthritis,
arthritis and asthma - osteoporosis, including senile osteoporosis, the one that accompanies
diabetes mellitus or corticosteroid treatment - high blood pressure.

- modulation of the immune system (suppression of proliferation
lymphocytes, differentiation of monocytes, etc ...) useful for the
treatment and prophylaxis in the case for example of diseases
autoimmune, inflammatory processes, as well as in the case of
organ transplantation. It is possible to use the compounds according to
the invention to prevent the rejection of transplants in use alone or in
combination with other compounds, such as cyclosporin, FK 506,
etc ...

kidney failure;
Other features and advantages of the invention will become apparent in the light of the description and examples which follow.

In the examples which follow, the derivatives of formula V have in particular been obtained according to one of the routes mentioned generally in the following scheme lb

Figure 1b
Three stages can be distinguished (a) the introduction of a fragment of the side chain containing a
function, possibly protected, which should allow the introduction of
epoxide; the fragment is advantageously introduced by
substitution of the tosylate group in lc, as described in
[30] (b) the introduction of the epoxide which can be made from an olefin of
type A 'by one of the conventional or conventional epoxidation methods
starting of a ketone type A using for example ylures
in which case the introduction of part of the chain together gives the epoxide (c) after possible deprotection of the hydroxyl group on the ring,
oxidation of the latter in ketone. It should be noted that, in general,
the epoxide formed will be present in two isomeric forms that it can
to be useful to separate.

 The isomeric forms at C-20 (see structure IIc, IId) are prepared in the same way but starting from the tosylate which is obtained from the corresponding isomeric primary alcohol 1b. The latter can be obtained from the following sequence (a) oxidation of the primary alcohol in for example by pyridinium hydrobromide perbromide (b) isomerization of aldehyde 2a with a base such as diazabicyloundecene (c) reduction of the mixture of aldehydes 2a and 2b with sodium borohydride and separation of alcohols 1a and 1b.

 In the examples and Scheme 2 below is explained the synthesis of precursors V of vitamin D3 derivatives according to the invention.

 The epoxide 5, obtained in the form of a mixture of diastereomers 5a and 5b, is obtained from tosylate 1c. The latter is prepared from alcohol 1a with tosyl chloride in pyridine. Alcohol results from ozonolysis, followed by reduction with sodium borohydride, vitamin D2 or vitamin D2 acetate according to a method described in the literature [31]. The tosylate 1c is then coupled with the organomagnesium derivative of 4-chloro-2-methyl-1-butene in the presence of Li2CuCl4 according to the process described for this derivative in the literature [32]. The epoxidation of the olefin 3 thus obtained is carried out conventionally with m-chloroperbenzoic acid in dichloromethane at room temperature. The mixture of the two epoxides 4a and 4b thus obtained is advantageously oxidized by pyridinium dichromate in dichloromethane. .

 The epoxide IIa, having an additional function in the side chain, can be selectively prepared from olefin 3.

After protecting the secondary alcohol in the form of timethylsilyl ether, the position 24 in the side chain is oxidized by selenium dioxide in the presence of tert-butyl hydroperoxide in dichloromethane. The resulting mixture of diastereomeric alcohols 7a and 7b is not separated at this stage.

a mCPBA, CH2Cl2. 25 C; b PDC. CH2Cl2. 25 C; c N.trimethylsilylimidazole. CH2Cl2, 25 C; d SeO2. tBuOOH. CH2Cl2. 25 C; e (+)-DIPT, Ti(OiPr)4. tBuOOH, CH2Cl2; e (-)-DiPT, Ti(OiPr)4, tBuOOH, CH2Cl2; f nBu4NF, THF. 255C; f Me2S; HCl, acetone; h (Li2CuCl4, THF; h DMSO, Et3N; i H2SO4, dioxane-H2O; j Me3S-l-, KOH, CH3CN
En effet l'époxydation selon la méthode de Sharpless [33] permet dans le cas présent, en utilisant en présence de (+)-diisopropyl-L tartrate du tert-butylhydropéroxyde et du Ti(i-PrO)4, la transformation sélective de l'alcool 7a en époxyde 8a, laissant l'alcool 7b inchangé. Ce dernier peut éventuellement être utilisé ensuite dans une époxydation telle que décrite pour l'oléfine 3.Après déprotection de l'alcool secondaire, le diol 9a est oxydé sélectivement à l'hydroxyle attaché au cycle. Enfin la fonction hydroxyle dans la chaîne latérale de la cétone 10a est protégée sous forme d'éther triméthylsilylique (1 la) en vue de son couplage.Figure 2

mCPBA, CH2Cl2. 25 C; b PDC. CH2Cl2. 25 C; ntrimethylsilylimidazole. CH2Cl2, 25 C; d SeO2. tBuOOH. CH2Cl2. 25 C; e (+) - DIPT, Ti (OiPr) 4. tBuOOH, CH2Cl2; e (-) - DiPT, Ti (OiPr) 4, tBuOOH, CH2Cl2; nBu4NF, THF. 255C; f Me2S; HCl, acetone; h (Li 2 CuCl 4, THF, h DMSO, Et 3 N, H 2 SO 4, dioxane-H 2 O, Me 3 S-1, KOH, CH 3 CN
Indeed epoxidation according to the method of Sharpless [33] allows in the present case, using in the presence of (+) - diisopropyl-L tartrate of tert-butylhydroperoxide and Ti (i-PrO) 4, the selective transformation of the epoxy alcohol 8a 8a, leaving the alcohol 7b unchanged. The latter may optionally be used subsequently in an epoxidation as described for the olefin 3. After deprotection of the secondary alcohol, the diol 9a is selectively oxidized to the hydroxyl attached to the ring. Finally, the hydroxyl function in the side chain of ketone 10a is protected in the form of trimethylsilyl ether (1 Ia) for coupling.

In a similar manner the protected epoxy ketone 15b, a stereoisomer of IIa, is prepared from the olefin 6. After the allylic oxidation, the mixture of alcohols 7a, 7b is deprotected. Oxidation of
Sharpless this time is performed on the mixture of diols 12a, 12b. In the presence of (-) - diisopropyl-D-tartrate, tert-butylhydroperoxide and
Ti (IV) isopropoxide the epoxidation is carried out selectively on 12b, leaving 12a unchanged. Epoxide 13b is then oxidized and the free hydroxyl group in ketone 14b is protected as a trimethylsilic ether for 15b coupling. also performs from tosylate lc. When the latter is treated with the Grignard derivative obtained from isopentenyl chloride in tetrahydrofuran in the presence of Li2Cu (II) C14, a mixture of the expected olefin 16 and an isomeric olefin 16 'is obtained. The latter is not an important product when iodide is used as the leaving group instead of a tosylate in the described step.

After conventional epoxidation the mixture of epoxides is obtained which can be separated. In this way the epoxidation of the secondary alcohol can be carried out on the derivatives 17a, 17b on the one hand, and on the derivatives 17'a, 17'b, on the other hand. The ketones 18a, 18b and 18'a, 18'b can be used directly in the coupling step.

 Finally acetylene 22a, 22b is obtained from the tosylate by substitution with the lithiated derivative obtained from the acetal of 3-butyn-2-one. After deprotection of the acetal at 19, the ketone is treated with a ylide obtained from trimethylsulfonium iodide. The epoxide in diastereomeric form 21a, 21b is oxidized and the corresponding ketones 22a, 22b can be coupled directly.

The synthesis of derivatives II of vitamin D3 by coupling of derivatives V with the anion of derivative IV is carried out according to scheme 3:
Schema 3

<tb><SEP> v <SEP> ll
<tb><SEP> II <SEP> II
<tb><SEP> Sa <SEP> + <SEP> zb <SEP> -CH2CH2- <SEP> CH3 <SEP> H <SEP> H <SEP> -CH2CH2- <SEP> SitBuMe2 <SEP> 23a <SEP> 1 <SEP> 23b
<tb><SEP> CH3 <SEP> H <SEP> H <SEP> -CH2CH2- <SEP> H <SEP> 24a <SEP> + <SEP> 24b
<tb><SEP> TMSO. <SEP> H <SEP> TMSO., <SEP> H
<tb><SEP> lia <SEP> sCH22 <<SEP> CH3 <SEP> H <SEP> H <SEP> XCHK <SEP> SitBuMe2 <SEP> 25a
<tb><SEP> CH2 <SEP> \ CH \ <SEP> CH2
<tb><SEP> CH3 <SEP> H <SEP> H <SEP> HO. <SEP> H <SEP> H
<tb><SEP> N
<tb><SEP> CH2
<tb><SEP> H <SEP> OTMS <SEP> H <SEP> OTMS
<tb><SEP> iSb <SEP> N <SEP> OTMS <SEP> CH3 <SEP> H <SEP> H <SEP> CH2 <SEP> SitBUMe2 <SEP> 27b
<tb><SEP> CH2 <SEP> CH2
<tb><SEP> CH3 <SEP> H <SEP> H <SEP> N <SEP> H <SEP> 0K <SEP> H <SEP> 2Sb
<tb><SEP> CH '
<tb> + <SEP> 18b <SEP> -CH2- <SEP> H <SEP> CH3 <SEP> CH3 <SEP> -CH2- <SEP> SitBUMe2 <SEP> 29a <SEP> + <SEP> 29b
<tb><SEP> H <SEP> CH3 <SEP> CH3 <SEP> -CH2 <SEP> - <SEP> H <SEP> 30a <SEP> + <SEP> lOb
<tb> 181a <SEP> + <SEP> 18b <SEP> -C (CH3- <SEP> H <SEP> H <SEP> H <SEP> -C (CH3) 2- <SEP> SitBuMZ2 <SEP >29't<SEP> + <SEP>29'b
<tb><SEP> H <SEP> H <SEP> H <SEP> -C (CH3) 2- <SEP> H <SEP>30'a<SEP> + <SEP>30'b
<tb><SEP> 22a <SEP> + <SEP> 22b <SEP> -CC- <SEP> CH3 <SEP> H <SEP> H <SEP> -C = -C- <SEP> SitBUMe2 <SEP> 31a <SEP> + <SEP> 31b
<tb><SEP> CH3 <SEP> H <SEP> H <SEP> -0 = -C- <SEP> H <SEP> 32r + <SEP> 32b
<Tb>
Coupling of ketones having the epoxide function in the side chain such as 5a / 5b and 1a with the anion of the derivative IV leads to protected derivatives such as 23a / 23b and 25a, respectively. The elimination of the protective groups of the coupling derivatives finally leads to obtaining the alcohols derived from formula II.

 An example is the condensation of the lithium salt, obtained from phosphonate IV with n-butyllithium in THF at -78 C with the mixture of diastereomers 5a and 5b, leading to the mixture of trienes 23a and 23b. The deprotection of the silylated ether groups is advantageously carried out with tetrabutylammonium fluoride. In the case of epoxide 1a the analogous coupling leads to 25a and, after deprotection, to triol 26a.

 In a completely analogous way the epoxide 15b leads via 27b to the triol 28b. The reaction of the mixtures of the diastereomers 18a and 18b, 18'a and 18'b, as well as 22a and 22b lead after coupling and deprotection to the mixtures of the diols 30a and 30b, 30'a and 30'b, and 32a and 32b, respectively.

EXAMPLE 1 Synthesis of epoxy-alcohols 4a, 4b
To a solution of 3 (0.16 g, 0.61 mmol) in dry dichloromethane (7 ml) was added m-chloroperbenzoic acid (mCPBA, 0.235 g, 1.36 mmol, 2.2 equivalents). ) and the solution was stirred for one hour at room temperature under an argon atmosphere. Potassium carbonate was added, stirring was continued for 10 minutes and the reaction mixture was filtered through a Merck bed.
Kieselgel 60 and Celite using the mixture n-hexane / ethyl acetate (7: 3). The filtrate was concentrated under reduced pressure and the oily residue was purified by HPLC on a 10 μm silica column with n-hexane / ethyl acetate (8: 2) as eluent. This gave the mixture of diastereoisomers 4a. and 4b (0.146 g, 0.52 mmol, 86%) as a white solid.

Characteristics: Rf (n-hexane / ethyl acetate, 7: 3): 0.31.

Spectroscopic data of 4a, 4b: IR (KBr-film): 3424 (s), 2943 (s), 2872 (s), 2285, 1461, 1444, 1390, 1373, 1266, 1170, 1066, 995, 943, 898 , 887, 858, 835, 802, 737 and 702 cm; 1H NMR (CDCl3, 360 MHz): 4.07 (1H, q, 2.6
Hz), 2.61 (1H, dd, 4.9, 2.9 Hz), 2.57 (1H, d, 4.9 Hz), 1.99 (1H, m), 1.82 (3H, m), 1.30 (3H, s), 0.92 (3H, s) and 0.90 (3H, d, 6.5Hz) ppm; MS: m / z at 262 (1), 247 (2), 234 (1), 180 (1), 179 (4), 162 (4), 151 (9), 136 (14), 125 (16) , 111 (100), 96 (27), 81 (40), 67 (36) and 55 (75).

EXAMPLE 2 Synthesis of Epoxy Ketones 5a and 5b
To a solution of 4a, 4b (0.146 g, 0.52 mmol) in dry dichloromethane (9 mL) was added pyridinium dichromate (PDC, 0.494 g, 1.31 mmol, 2.5 equivalents) and a quantity of Catalyst of pyridinium para-toluenesulfonate (PPTS) and the suspension was stirred for 4 hours at room temperature under an argon atmosphere. Ether was added (from 10 ml) and stirring continued for 5 minutes, the reaction mixture was filtered through a bed of Merck
Kieselgel 60 and celite using ether, and the chromium salt precipitates were washed several times with ether and then filtered.The mixed filtrates were concentrated under reduced pressure and the residue was purified by HPLC on a 10 μm silica column eluted with n-hexane / ethyl acetate (85:15). The mixture of diastereoisomers 5a and 5b (0.139 g, 0.5 mmol, 96%) was thus obtained as an oil.

Characteristics: Rf (n-hexane / ethyl acetate, 7: 3): 0.35.

Spectroscopic data of 5a, 5b: IR (KBr-film): 3034, 2956 (s), 2873 (s), 1714 (s), 1456, 1378, 1307, 1255, 1234, 1187, 1152, 1107, 1056, 943 , 902, 838, 795, 737 and 703 cm -1 NMR (CDCl3, 360 MHz): 2.61 (1H, dd, 4.9, 2.8 Hz), 2.58 (1H, d, 4.9 Hz), 2.44 (1H, dd, 11.6, 7.5Hz), 2.26 (2H, m), 2.12 (1H, ddd, 12, 4.1, 2.5Hz), 2 (1H, m), 1.90 (2H, m), 1.78 (1H, m), 1.31 (3H, s), 0.96 (3H, d, 6.1Hz), and 0 63 (3H, s) ppm; MS: m / z at 278 (M- +, 1), 263 (2), 250 (2), 235 (2), 204 (2), 177 (4), 159 (4), 125 (24), 111 (36), 85 (24), 81 (52), 67 (39) and 55 (100).

EXAMPLE 3 Syntheses of 25 (S) -1-alpha-hydroxy-25,26-epoxy-vitamin D3 (24a) and 25R-1 alpha-hydroxy-25,26-epoxy-vitamin D3 (24b).

 A solution of IV (0.053 g, 0.091 mmol, 1.3 equivalents) in anhydrous tetrahydrofuran (0.5 mL) was placed under an argon atmosphere (1.1 bar), cooled to -70 ° C, and dried. Butyllithium (2.41 M solution in n-hexane, 0.037 ml, 0.087 mmol) was added, the resulting dark solution was stirred for 30 minutes, then the ketones 5a and 5b were added dropwise (0.degree. 02 g, 0.072 mmol) dissolved in anhydrous tetrahydrofuran (0.9 ml) The mixture was stirred at -70 ° C for 1.5 hours then allowed to come to room temperature over a period of 2.5 hours. Two or three drops of water were added to the red solution and most of the solvents were removed under argon flow. A solution of saturated sodium bicarbonate (2 ml) was added and extracted three times with diethyl ether ( 2 ml), the combined extracts were filtered through a bed of Merck Kieselgel 100 (35-70 mesh) and the solvent was removed under reduced pressure. The residue was chromatographed rapidly on a 10 μm silica HPLC column with n-hexane / ethyl acetate (85:15) as eluent. The oil obtained (mixture of 23a and 23b) was immediately taken up in anhydrous tetrahydrofuran (0.3 ml), tetrabutylammonium fluoride (TBAF, 1M solution in 0.255 ml tetrahydrofuran) was added and the solution was dissolved. stirred for 15 hours at room temperature under an argon atmosphere, protected from light. The solvent was removed under argon flow and the residue was chromatographed on Merck Kieselgel 60 with dichloromethane / methanol (9: 1) as eluent. Further purification by HPLC (10 μM silica, dichloromethane / methanol (92.5: 7.5)) gave the mixture of diastereoisomers 24a and 24b (0.019 g, 0.046 mmol, 64%).

Characteristics: Rf (dichloromethane / methanol 9: 1): 0.41.

Spectroscopic data of 24a, 24b: UV (MeOH) 2 max = 261 nm; IR (KBrfilm): 3380 (s), 3048, 2946 (s), 2870 (s), 1644, 1446, 1377, 1266, 1218, 1148, 1055, 957, 898, 799, 737 and 703 cm; 1H NMR (CDCl3, 360MHz): 6.38 (1H, d, 11.2Hz), 6.01 (1H, d, 11.2Hz), 5.32 (1H, m), 5 (1H, m), 4.44 (1H, dd, 7, 4.3 Hz), 4.22 (1H, ddd, 10, 7.4 Hz), 2.82 (1H, dd, 11.5, 3.5. Hz), 2.61 (1H, dd, 4.8, 2.3 Hz), 2.57 (1H, d, 4.8 Hz), 2.31 (1H, dd, 13.4, 6.6). Hz), 1.81-2.05 (4H, m), 1.31 (3H, s), 0.93 (3H, d, 6.4Hz) and 0.54 (3H, s) ppm; MS: m / z at 415 (M- +, 1, 2), 397 (2), 378 (2), 287 (1), 267 (2), 251 (3), 197 (3), 171 (5), ), 152 (24), 134 (60), 105 (31), 91 (42), 81 (40), 79 (40), 67 (35) and 55 (100).

EXAMPLE 4 Synthesis of Alcohols 7a and 7b
To a solution of 3 (600 mg, 2.27 mmol) and N- (trimethylsilyl) imidazole (953 mg, 6.81 mmol, 997 μl) in anhydrous CH 2 Cl 2 (8 ml) was stirred at room temperature under an atmosphere. nitrogen for 3 hours. After concentration, a residue was obtained which was directly chromatographed (hexane / EtOAc, 16: 1) to give 6 as an oil (672 mg, 88%).

Characteristics: Rf (hexane / EtOAc 8: 2): 0.95.

Spectroscopic data of 6: 1H NMR (CDCl3, 360 MHz): 0.05 (9H, s), 0.88 (3H, s), 0.89 (3H, d, 6.64Hz), 1.71 ( 3H, s), 3.99 (1H, m), 4.66 (1H, bs), 4.68 (1H, bs) ppm.

A mixture of selenium dioxide (33 mg, 0.30 mmol), t-butylhydroperoxide (90%, 90 mg, 0.90 mmol) and anhydrous CH2 Cl2 (4 mL) was stirred at 25 ° C for half an hour. hour. A solution of 6 (200 mg, 0.60 mmol) in anhydrous CH 2 Cl 2 (4 mL) was added for several minutes. The resulting mixture was stirred at 25 ° C under nitrogen for half an hour.

Stirring was continued at about -20 C for 22 hours. The reaction proceeded to room temperature, methyl sulfide (1 ml) was added, the resulting mixture was stirred at 25-30 ° C for 5 hours. The reaction mixture was filtered through a small silica gel, the concentration of the filtrate gave a residue which was directly chromatographed (hexane / EtOAc 16: 1) to give 6 (9 mg, 4.5%) and a mixture of diastereoisomers 7a and 7b in the form of an oil (63 mg, 30%),
Characteristics: Rf (hexane / EtOAc, 9: 1): 0.36. [?] 26D + 45.83 (c 1.857, CHCl3).

Spectroscopic data of 7a and 7b: 1H NMR (CDCl3, 360 MHz): 0.04 (9H, s), 0.87 (3H, s), 0; 90 (3H, d, 6.51Hz), 1, 72 (SH, s), 4 (2H, m), 4.83 (1H, d), 4.92 (1H, m) ppm.

EXAMPLE 5 Synthesis of Alcohol 7b and Epoxide 8a
To a solution of 7a, 7b (90mg, 0.256mmol) and (+) - diisopropyltartrate (9mg, 0.038mmol) in anhydrous CH2Cl2 (1.5ml) was added sieves of 4 reactivated powder (27mg). ). The stirred mixture, maintained under a nitrogen atmosphere, was cooled from -10 to -20 ° C., treated with titanium (IV) isopropoxide (7.4 mg, 0.026 mmol) and stirred for 30 minutes at room temperature. C. The reaction was then treated with a solution of tert-butyl hydroperoxide in isooctane (7 M, 0.179 mmol, 26 μl, dried with 3 R pellets activated freshly for 30 minutes before addition). and poured with a syringe.The reaction was stirred at about -20 ° C for 27 hours.

An aqueous solution of ferrous sulfate and tartaric acid (2 ml) was cooled to 0 ° C and treated dropwise with the reaction mixture. The two-phase mixture was stirred for 10 minutes and the aqueous solution extracted with two portions of ether (4 ml). The organic phase was treated with 2 ml of pre-cooled solution at 0 ° C. 30% NaOH in saturated brine. The two-phase mixture was stirred vigorously for 1 hour at 0 ° C. and, after dilution with water (3 ml), the layers were separated and the aqueous layer was extracted with ether (2 × 10 ml) . The mixed organic phase was washed with brine and then dried over MgSO4.

After filtration and concentration a residue was obtained which was separated by
HPLC (hexane / EtOAc, 9: 1) to give a pure 7b oil (27 mg) and crude product 8a. The latter was purified by HPLC (hexane / EtOAc, 9.5: 1) to give pure product 8a as white crystals (38 mg).

7h compound
Characteristics: Rf (hexane / EtOAc, 8: 3) = 0.72; [?] 22D + 56.05 (c 1.140, CHCl3). Spectroscopic data: IR (KBr-Film): 3360 (s, br), 3072 (w), 1650, 908 (s) cm H NMR (360 MHz, CDCl 3): 0.05 (9H, s), 0, 88 (3H, s), 0.90 (3H, d, 6.53Hz), 1.72 (3H, s), 3.99 (2H, m), 4.83 (1H, t), 4, 93 (1H, t) ppm; MS: m / z 334 (2), 309 (3), 262 (1), 223 (8), 197 (12), 183 (75), 73 (100).

Compound 8a
Characteristics: Rf (hexane / EtOAc, 8: 3) = 0.55; [?] 20D + 46.81 (c 1.177, CHCl3); mp: 65-66 C. Spectroscopic data: IR (KBr-Film): 3479 (s, br), 1250 (s), 839 (s), 745 cl; 1H NMR (360 MHz, CDCl3): 0.04 (9H, s), 0.87 '(3H, s), 0.91 (3H, d, 6.57Hz), 1.34 (3H, s) , 2.61 (1H, d, 4.77Hz), 2.89 (1H, d, 4.77Hz), 3.56 (1H, m), 3.99 (1H, m) ppm; MS: m / z 368M +; 1), 295 (2), 223 (3), 197 (11), 183 (66), 73 (100).

EXAMPLE 6 Synthesis of Diol 9a
A solution of 8a (34mg, 0.02mmol) and tetrabutylammonium fluoride (1M solution in THF, 0.46mmol, 460, ul) in
THF (2 mL) was stirred at room temperature for 2.5 hours.

After removal of THF under reduced pressure, the residue was treated with ether and the mixture washed with brine then dried over MgSO4.

After filtration and concentration, a residue was obtained which was chromatographed (hexane / EtOAc, 6: 4) to give an oily and viscous compound 9a (26 mg, 96%).

Characteristics: Rf (hexane / EtOAc, 6: 4) = 0.38.

Spectroscopic data of 9a: 1H NMR (360 MHz, CDCl3): 0.92 (3H, d, 6.26 Hz), 0.92 (3H, s), 1.34 (3H, s) 2.60 (1H , d, 4.78 Hz), 2.88 (1H, d, 4.78 Hz), 3.55 (1H, m), 4.07 (1H, m) ppm.

EXAMPLE 7 Synthesis of Epoxyketone 10a
A mixture of 9a (25 mg, 0.084 mmol), pyridinium dichromate (47 mg, 0.125 mmol) and anhydrous CH 2 Cl 2 (2 mL) was stirred at room temperature under nitrogen for 2 hours. The mixture was chromatographed (hexane: EtOAc / CH3COCH3, 6: 4: 0.5) to give the crude product 10a which was purified by HPLC (hexane / EtOAc, 6: 4) to give pure oil 10a ( 20 mg, 81%).

Characteristics: Rf (hexane / EtOAc, 6: 4) = 0.36.

Spectroscopic data of 10a: IR (KBr-Film): 3444 (s, br), 1709 (s), 1236, 906, 812 cm-1; 1H NMR (500 MHz, CDCl3): 0.63 (3H, s), 0.97 (3H, d, 6.22Hz), 1.34 (3H, s), 2.45 (1H, dd, 7H NMR (CDCl3):? , 45 Hz, 11.70 Hz), 2.60 (1H, d, 4.81 Hz), 2.87 (1H, d, 4.81 Hz), 3.55 (1H, d, 8.36 Hz) ) ppm.

EXAMPLE 8 Synthesis of the protected epoxyketone 1
A solution of 10a (18 mg, 0.061 mmol) and N- (trimethylsilyl) imidazole (26 mg, 0.186 mmol, 27 μl) in anhydrous CH 2 Cl 2 (1.5 mL) was stirred at room temperature under a nitrogen atmosphere. during 2 hours. The mixture was chromatographed (hexane / EtOAc, 9: 1) to give compound 11a as an oil (20 mg, 89%).

Characteristics: Rf (hexane / EtOAc, 8: 2) = 0.48.

Spectroscopic data for 1 H NMR (360 MHz, CDCl 3): 0.09 (9H, s), 0.63 (3H, s), 0.96 (3H, d, 6.06 Hz), 1.28 ( 3H, s), 2.44 (1H, dd, 7.48Hz, 11.64).
Hz), 2.56 (1H, d 5.12 Hz), 2.65 (1H, d, 5.12 Hz), 3.17 (1H, dd, 3.29 Hz, 8.88).
Hz) ppm.

EXAMPLE 9 Synthesis of (24S, 25R) -1-alpha124-dihydroxy-25,26-epoxy-vitamin D3 (26a)
To a stirred solution of IV phosphine oxide (57 mg, 0.098 mmol) in anhydrous THF (0.8 mL) at -80 ° C under argon was added n-BuLi (a 2.46M solution). in hexane, 0.098 mmol, 40 μl) giving a dark orange solution. The mixture was stirred again for 1 hour. The compound 11a (18 mg, 0.049 mmol) of anhydrous THF (0.8 ml) was then added dropwise to the solution. The mixture was stirred at -80 ° C for 2 hours. The solution was warmed slowly to room temperature, during which time the color turned pale yellow and eventually became almost colorless. The mixture was chromatographed (hexane / EtOAc, 12: 1) to give the crude product which was purified by HPLC. (hexane / EtOAc, 14: 1) to give the pure product 25a as an oil (32 mg, 89%).

Characteristics: Rf (hexane / EtOAc, 9: 1) = 0.78.

A solution of 25a (32 mg, 0.044 mmol) and tetrabutylammonium fluoride (0.44 mmol, 440, ul, 1M solution in THF) in THF (2 mL) was stirred at room temperature under nitrogen, in the dark, for 3 hours and a half. Tetrabutylammonium fluoride (440 μl of a 1M solution, 0.44 mmol) was added and the resulting mixture stirred for 6 hours. Ether was added, the mixture was washed with brine and the aqueous phase extracted twice with ether. The combined organic phases were dried over MgSO 4. After filtration and concentration, a residue was obtained which was filtered through a small column of silica gel by eluting with 100 ml of 5% CH 3 OH in CH 2 Cl 2. Concentration of the filtrate gave a residue which was purified by
HPLC (95: 5 CH2Cl2 / CH3OH) to give the pure product 26a (16 mg, 85%).

Characteristics: Rf (CH2Cl2 / CH3OH 9.5: 0.5) = 0.30.

Spectroscopic data for 26a: UV (CH3OH): max = 263 nm; IR (KBr-Film): 3379 (s, br), 1643 (br), 1059 (s) 896, 800, 736 from; 1H NMR (500 MHz, CDCl3): 0.54 (3H, s), 0.95 (3H, d, 6.52Hz), 1.34 (3H, s), 2.60 (1H, d, 4). , 78 Hz), 2.88 (1H, bs), 5.32 (1H, bs), 6.01 (1H, d, 11.26 Hz), 6.37 (1H, d, 11.26 Hz) ppm; MS: m / z 431 (M + +1, 2), 394 (1), 382 (2), 355 (2), 337 (2), 285 (1), 251 (4), 227 (3), 197 (5), 134 (100).

Example 10 Synthesis of Diols 12a, 12b
A mixture of 31 mg (0.28 mmol) of selenium dioxide, 83 mg is stirred at approximately 25 ° C. under nitrogen for 0.5 hour.
(0.93 mmol) of tert-butyl hydroperoxide (90%) and 5 ml of dichloromethane. A solution of 1.85 mg (0.55 mmol) of 6 in 5 ml of dichloromethane is added over several minutes. The mixture obtained is stirred at approximately 25 ° C. for 0.5 hour. Stirring is continued at -200C for 22 hours. 1 ml of methyl sulphide is added, and the mixture is stirred at 25-300 ° C. for 4 hours. The dichloromethane is removed with a rotary evaporator. 4 ml of acetone is added to the residue, 10% hydrochloric acid is added dropwise to pH 3. The mixture is stirred at 250 ° C. for 1 hour, then neutralized with saturated aqueous NaHCO 3, extracted with ether and dried over MgSO4. Concentrated to obtain a residue which is subjected to flash chromatography (hexane / EtOAc 10/3) to obtain 63 mg (41%) of 12a, 12b in the form of crystals. white.

Rf (hexane / EtOAc: 7/3): 0.38; [&alpha;] D18 + 35.820 (c = 1.329; CHCl3); mp 94-1080C.

Spectral values of 12a, 12b: IR (KBr-film): 388 (F, broad), 3072 (f), 1650, 899 cm1.

1H-NMR (360 MHz, CDCl3): 0.91 (d, 6.56Hz, 3H), 0.93 (s, 3H), 1.72
(s, 3H), 4.01 (t, 1H), 4.07 (bs, 1H), 4.83 (d, 1H), 4.92 (m, 1H) ppm.

Example 11 Synthesis of Alcohol 12a and Epoxide 13b
To a solution at room temperature of 90 mg (0.32 mmol) of 12a, 12b and 11.23 mg (0.048 mmol) of diisopropyl (-) - tartrate in 2 ml of anhydrous dichloromethane, 27 mg of sieves are added. 4A pulverized and activated. The stirred mixture maintained under nitrogen was cooled to -10 ° to -200 ° C., treated with 9.09 mg (0.032 mmol) of
Ti (oi-Pr) 4 and stirring is continued for 30 minutes at -200 ° C. The reaction mixture is then treated with a solution of tert-butyl hydroperoxide in isooctane (7.00 M, 0.224 mmol; Z1, dried with freshly activated 3A pellets for 30 minutes before addition), which is added using a gas-tight syringe. The reaction mixture is stirred at about -200 ° C. with a bath maintained at a constant temperature for 23 hours. 10 ml of an aqueous suspension of ferrous sulphate and tartaric acid are cooled to about 0.degree. C. with the aid of an ice-water bath. The mixture of the epoxidation reaction is allowed to warm to about 0.degree. then poured slowly into a beaker containing the stirred chilled ferrous sulphate solution (external cooling is not essential during or after this addition). The two-phase mixture is stirred for about 10 minutes and then transferred to a separatory funnel. The phases are separated and the aqueous phase is extracted with two portions of 6 ml of ether. The combined organic layers are treated with 3 ml of a previously cooled solution (0 C) of 30% NaOH in saturated saline water. The two-phase mixture is stirred vigorously for 1 hour at 0 ° C. After transfer to a separatory funnel and dilution with 3 ml of water, the phases are separated and the aqueous layer is extracted with two 15 ml portions of ether. The combined organic layers are washed with saturated aqueous NaCl and dried over MgSO 4. Filter and concentrate to obtain a residue which is separated by HPLC (hexane / EtOAc: 7/4) to obtain 32 mg of optically pure 13b in the form of white crystals, 4 mg of a stereoisomer of 13b ( characterized by 1 H-NMR) and 55 mg of crude 12a as white crystals still containing the 24- (R) -isomer (according to 1H-NMR at 500 MHz). The crude product 12a is subjected to a second Sharpless kinetic resolution to obtain 33 mg of optically pure 12a.

For 12a: Rf (hexane / EtOAc: 1/1): 0.61; [D18 + 32.580 (c = 1.016, CHCl3); m.p. 121.5-123.50C.

Spectral values: IR (KBr-film): 3374 (F, broad), 3073 (f), 651 (f), 899 cm-1.

1 H-NMR (500 MHz, CDCl 3): 0.91 (d, 6.56 Hz, 3H), 0.93 (s, 3H), 1.72 (s, 3H), 4.02 (t, 1H) , 4.07 (bs, 1H), 4.83 (t, 1H), 4.92 (t, 1H) ppm.

MS: m / z 280 (M +: 0.04), 262 (10.8), 247 (5.8), 229 (5.7), 190
(6.3), 163 (15.9), 135 (43.2).

For 13b: Rf (hexane / EtOAc: 1/1): 0.44; [D20 + 40.890 (c = 1.010, CHCl3); mp 97-980C.

Theoretical analysis for C18H32O3: C = 72.97; H, 10.81; found
C = 72.83; H = 10.85.

Spectral values: IR (KBr-film): 440 (F, broad), 126, 942, 756 cm1.

1H-NMR (500 MHz, CDCl3): 0.93 (s, 3H), 1.34 (s, 3H), 2.60 (d, 4.78 Hz, 1H), 2.89 (d, 4, 78 Hz, 1H), 3.61 (m, 1H), 4.07 (bs, 1H) ppm.

MS: m / z 278 (0.7), 263 (1.3), 260 (0.7), 245 (0.7), 193 (2), 177
(4,7), 161 (7.3), 135 (17.4), 111 (100).

Example 12. Synthesis of Epoxyketone 14b
A mixture of 25 mg (0.084 mmol) of 13b, 63 mg (0.168 mmol) of pyridinium dichromate (DCP) and 2.5 ml of dichloromethane is stirred at 0 ° C. under nitrogen for 4 hours. 16 mg (0.043 mmol) of DCP are added, then the reaction mixture is allowed to return to room temperature and stirred for 2 hours. The mixture is flashed directly (hexane / EtOAc 6/4) to obtain 20 mg of 14b as white crystals (80%).

Rf (hexane / EtOAc: 6/4): 0.33; mp 84-850C.

Spectral values of 14b: IR (KBr-film): 3446 (F, broad), 1711 (F), 126, 942, 814 cm-1.

1 H-NMR (360 MHz, CDCl 3): 0.64 (s, 3H), 0.97 (d, 5.53 Hz, 3H), 1.34 (s, 3H), 2.45 (dd, 11, 64 Hz, 7.48 Hz, 1H), 2.60 (d, 4.75 Hz, 1H), 2.89 (d, 4.75 Hz, 1H) 3.61 (d, 1H).

Example 13 Synthesis of Epoxyketone 15b
A solution of 20 mg (0.068 mmol) of 14b and 19 mg (0.136 mmol, 20 μl) of N- (trimethylsilyl) imidazole in 2 ml of CH 2 Cl 2 was stirred under nitrogen at room temperature for 1 hour. The mixture is then flashed directly (hexane / EtOAc: 9/1) to give 22 mg of 15b as an oil (88%).

Rf (hexane / EtOAc: 8/2): 0.49.

Spectral values of 15b: 1H-NMR (500 MHz, CDCl3): 0.09 (s, 9H), 0.63 (s, 3H), 0.96 (d, 5.98 Hz, 3H), 1.28 (s, 3H), 2.45 (dd, 11.61 Hz, 7.49 Hz, 1H), 2.56 (d, 5.12 Hz, 1H), 2.67 (d, 5.12 Hz, 1H), 3.22 (dd, 8.56 Hz, 3.62 Hz, 1H) ppm.

Example 14 Synthesis of (34R, 25S) -1α, 24-dihydroxy-25,26-epoxy-
vitamin D3 (28b)
To a stirred solution of 54 mg (0.093 mmol) of phosphine oxide IV in 0.6 ml of anhydrous THF under nitrogen at -800 ° C., n-BuLi (2.5 M solution in hexane, 0.093 mmol) is added. 37 pl) to obtain a dark orange solution. The mixture is stirred under these conditions for 1 hour. 17 mg (0.046 mmol) of 15b in 0.8 ml of anhydrous THF are slowly added dropwise to the solution. The mixture obtained is stirred at -800 ° C. for 2 hours. The solution is allowed to warm slowly to room temperature, while it turns pale yellow and finally becomes almost colorless. The mixture is flashed directly (hexane / EtOAc: 12: 1) to obtain crude 27b. it is further purified by HPLC (hexane / EtOAc: 18/1) to obtain 28 mg (82%) of pure 27b as an oil.

Rf (hexane / EtOAc: 9/1): 0.74.

 A solution of 28 mg (0.038 mmol) of this latter compound and (n-Bu) 4NF (1 M solution in THF, 0.75 mmol, 760 l) in 1 to 5 ml of THF is protected from light. it is stirred at room temperature under nitrogen for 9 hours. The mixture is filtered directly through a short column of silica gel eluting with 100 ml of CH 3 OH to 10 8 in CH 2 Cl 2. Concentration gives a residue which is separated by HPLC (CH 2 Cl 2 / CH 3 OH: 95/5) to obtain 12 mg of pure 28b as a white solid (73%).

Rf (CH 2 Cl 2 / CH 3 OH: 9.5 / 0.5): 0.29; [&alpha;] D18 = 32.37 (c = 1.035,
CHCl3).

 Spectral values of 28b: W (CH 3 OH): 4 = 262 nm.

1 H-NMR (500 MHz, CDCl 3): 0.55 (s, 3H), 0.94 (d, 6.50 Hz, 3H), 1.34 (s, 3H), 2.31 (dd, 13, 43 Hz, 6.63 Hz, 1H), 2.60 (d, 4.77 Hz, 1H), 2.89 (d, 4.77 Hz, 1H), 3.61 (m, 1H), 4, 22 (bs, 1H), 4.43 (bs, 1H), 5.00 (bs, 1H), 5.32 (t, 1H), 6.02 (d, 11.27 Hz, 1H) , 6.38 (d, 11.27 Hz, 1H) ppm.

 MS: m / z 394 (2), 336 (2), 251 (3).

Example 15 Synthesis of Alkenols 16 and 16 '
To a solution of 0.47 g (1.28 mmol) of 16 in 5.0 ml of tetrahydrofuran at -780C under argon is added dropwise 6.0 ml of a 1.25 M solution of chloroform. isopenténylmagnésium
(7.5 mmol, 6 equivalents), followed by 6.4 ml of a 0.1 M solution of dilithium (II) dilbitium tetrachloride (0.64 mmol, 0.5 equivalents) in tetrahydrofuran. The reaction mixture was allowed to warm to room temperature, stirred for a further 16 hours, then poured into 50 ml of saturated ammonium chloride solution. The aqueous layer is extracted several times with diethyl ether and the combined ether layers are washed with saturated sodium chloride solution, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. on silica gel and on a 10 m silica column with a mixture of isooctane / ethyl acetate (9/1) as eluent, in both cases to obtain the isomeric alcohols 16 and 16 '(0). 31 g, 92%) as a mixture (3/7 according to the 1 H-NMR spectrum).

Rf (isooctane / ethyl acetate: 9/1): 0.20.

Spectral values of 16: IR (KBr-film): 3,403 (F), 2,936 (F), 2,867 (F), 1,641, 1,445, 1,376, 1,268, 1,234, 1,165, 1,118 , 1,065, 1,035, 990, 942, 912, 886, 858, 822, 787, 725, 698 and 668 cm -1.

1 H-NMR (CDCl 3: 360 NHz): 5.09 (1H, t, 7.1 Hz, LR 1.4 Hz), 4.07 (1H, brs), 2.01 (2H, m), 1 , 83 (4H, m), 1.68 (3H, brs), 1.60 (3H, brs), 0.93 (3H, s) and 0.91 (3H, d, 6.5Hz) ; MS: m / z at 264 (N +: 2), 249 (3), 246 (3), 231 (4), 179 (7), 161 (12), 151 (26), 133 (22), 125 ( 11), 111 (28), 95 (21), 84 (43), 69 (46), 55 (44) and 49 (100).

Spectral values of 16 '(for a 3/7 mixture of 16/16'):
IR (KBr-film): 42020 (F), 3081 (F), 2868 (F), 1656, 1638, 1546, 1453, 1413, 1378, 1,361, 1,268, 1,234; , 1,165, 1,066, 1032, 991, 959, 941, 908, 885, 858, 820, 785, 725 and 692 cm1.

1 H-NMR (CDCl 3, 360 MHz): 5.79 (1H, dd, 17.8, 10.4Hz), 4.89 (1H, m), 4.85 (1H, m), 4.05 ( 1H, brs), 0.98 (3H, s), 0.97 (3H, s), 0.93 (3H, s) and 0.91 (3H, d, 6.5Hz).

 MS: m / z at 264 (M +: 2), 249 (4), 246 (4), 231 (5), 179 (9), 161 (15), 151 (34), 133 (27), 125 ( 18), 111 (60), 95 (34), 81 (39), 69 (74), 55 (82) and 43 (100).

Example 16. Synthesis of epoxy alcohols 17a, 17b and 17'a, 17'b
To a solution of 0.29 g (1.1 mmol) of a 3/7 mixture of 16 and 16 'in 13 ml of anhydrous dichloromethane is added 0.43 mg (2.1 mmol) of m-acid. -choroperbenzoic acid (AmCPB) and the solution is stirred for 3 hours at room temperature. 0.5 g of potassium carbonate is added, stirring is continued for 15 minutes, the reaction mixture is filtered and the remaining solid is washed with dichloromethane and filtered. The combined filtrates are concentrated under reduced pressure and the residue is purified on silica gel and on a 10 μm silica HPLC column, eluting with a 3/2 mixture of isooctane / ethyl acetate, in both cases. to obtain 0.21 g (68%) of 17a, 17b and 17'a, 17'b as a mixture.

Rf (isooctane / ethyl acetate: 8/2): 0.18.

 Chromatography of this mixture on a reverse phase CtHP column consisting of 10 μM RSilC18HL with 8/2 methanol / water as eluent provided 0.131 g of 17'a and 17'b diastereoisomers. Additional purification of the remaining material on a 10 μl silica CtHP column with 8/2 isooctane / ethyl acetate as eluent affords 0.025 g of the 17α and 17b diastereoisomers.

Rf (isooctane / acetone: 9/1): 17a, 17b: 0.19; 17'a, 17'b: 0.23.

Spectral values of 17a, 17b: IR (KBr-film): 3465 (F), 2933 (F), 1455, 1378, 1327, 1,266, 1,251, 1,180, 1,166, 1,118, 1,066, 1,035, 992, 943, 899, 859, 792, 737, 701 and 680 cm -1.

 1H-RMII (CDCl3, 360 NHz): 4.07 (1H, brs), 2.68 (1H, t, 6.0Hz), 1.99 (1H, dm, 11.9Hz), 1, 93-1.75 (3H, m), 1.30 (3H, s), 1.26 (3H, s), 0.93 (3H, s) and 0.91 (3H, d, 6.5Hz). ).

 MS: m / z at 280 (M +: 1), 265 (3), 262 (5), 247 (3), 229 (4), 219 (4), 179 (5), 161 (10), 151 ( 20), 133 (20), 125 (16), 111 (60), 95 (32), 81 (41), 67 (38), 55 (72) and 43 (100).

Spectral values of 17'a, 17'b: IR (KBr-film): 3454 (F), 2930 (F), 2870 (F), 1472, 1403, 1375, 1362, 1,267 , 1,167, 1,067, 1,033, 1,018, 992, 942, 913, 886, 859, 835, 784, 722, 688, 668 and 658 cm -1H-NMR (CDCl3, 360 MHz): 4.06 (1H broad), 2.74 (1H, dd, 4.0, 3.0 Hz), 2.62 (2H, m), 2.00 (1H, dm, 13.2 Hz), 1H, m), 1.81 (2H, m), 0.99 + 0.97 (3H, 2 xd, 6.2Hz), 0.96 (3H, s), (0.89 + 0.87) (3H, 2 xs) and 0.83 + 0.81 (3H, 2 xs).

 MS: m / z at 262 (1), 247 (2), 219 (1), 203 (1), 191 (2), 179 (4), 162 (6), 151 (8), 135 (15) , 125 (19), 111 (66), 95 (34), 81 (37), 69 (45) and 55 (100).

Example 17. Synthesis of epoxyketones 18a, 18b
To a solution of 0.021 g (0.075 mmol) of 17a, 17b in 2.0 ml of anhydrous dichloromethane was added 0.079 g (0.21 mmol, 2.8 equivalents) of pyridinium dichromate (DCP) and a catalytic amount of pyridinium p-toluenesulfonate (PTSP) and the suspension is stirred for 4.5 hours at room temperature under argon.

3 ml of diethyl ether are added, the stirring is continued for 5 minutes, the reaction mixture is filtered through a bed of Celite / silica gel using ether and the precipitated chromium salts are washed several times with ether and filtered. The combined filtrates are concentrated under reduced pressure and the residue is purified by HPLC on a 10 m silica column eluting with a 9/1 mixture of isooctane / acetone. 0.017 g (80% of the mixture of diastereoisomers 18a and 18b are thus obtained in the form of an oil).

Rf (isooctane / acetone: 9/1): 0.25.

Spectral values of 18a, 18b: IR (KBr-film): 2958 (F), 2875 (F), 1714 (F), 1462, 1378, 1324, 1308, 1242, 1223, 1,191,
I 172, 1120, 1056, 943, 900, 867, 837, 794 and 680 cm -1.

 1H-RHN (CDCl3, 360MHz): 2.67 (1H, t, 6.0Hz), 2.45 (1H, ddd, 11.5, 7.2, 2.9Hz), 2.32- 2.16 (2H, m), 2.11 (1H, dm, 13.2Hz), 2.05-1.82 (3H, m), 1.73 (1H, m), 1.30 (3H); , s), 1.26 (3H, s), 0.97 (3H, d, 6.0 Hz) and 0.64 (3H, s).

 MS: m / z at 278 (M +: 2), 260 (3), 235 (3), 205 (6), 192 (6), 177 (8), 149 (24), 135 (10), 124 (20); ), 111 (40), 96 (36), 81 (48), 67 (36), 55 (72) and 41 (100).

Example 18. Synthesis of 24 (S) -1- &alpha; -hydroxy-24,25-epoxyvitamin D3
(30a) and 24 (R) -24,25-epoxy-1α-OH-vitamin D3 (30b)
A solution cooled to -70 ° C. of 0.06 g (0.103 mmol, 2.05 equivalents) of IV in anhydrous tetrahydrofuran (1.0 ml) was placed under an atmosphere of 1.1 bar of argon and 0.039 ml of toluhydrofuran was added. a 2.5 M solution of n-butyllithium in n-hexane (0.096 mmol). The dark red solution obtained is stirred for 30 minutes. 0.014 g (0.05 mmol) of the 18a, 18b ketones dissolved in 0.5 ml of anhydrous tetrahydrofuran are added dropwise. The mixture is stirred at -700C for 1.5 hours and then allowed to warm to room temperature. a period of 2.5 hours. 2 to 3 drops of water are added to the still red solution and most of the solvents are removed under a stream of argon. 2.0 ml of a saturated solution of sodium bicarbonate is added and extracted several times with 2.0 ml of diethyl ether. The combined extracts are filtered through a bed of Merck Kieselgel 60 and the solvent is removed under reduced pressure. The residue is rapidly chromatographed on a column of
HPLC silica 10 with 85/15 mixture of n-hexane / ethyl acetate as eluent. The oil obtained (mixture of 29a and 29b) is immediately taken up in 0.4 ml of anhydrous tetrahydrofuran, 0 2 ml of a 1M solution of 1M tetrabutylammonium fluoride (FTBA) in tetrahydrofuran and the solution is stirred for 19 hours at room temperature under argon in the dark. The solvent is removed under a stream of argon and the residue is chromatographed on Merck Kieselgel 60 with a 9/1 mixture of dichloromethane / methanol as eluent. Additional purification by HPLC (10% silica, 95/5 dichloromethane / methanol) affords 0.018 g (86%) of the mixture of diastereoisomers 30a and 30b as a glassy material.

Rf (dichloromethane / methanol: 9/1): 0.36.

Spectral value of 30a, 30b:
W (MeOH) N max = 263 nm.

IR (KBr-film): 3,409 (F), 2,951 (F), 2,298 (F), 1,647, 1,447, 1,379, 1,266, 1,056, 958, 896, 800, 738 and 703 cm. -1.

 1 H-NMR (CDCl 3, 360 MHz): 6.37 (1H, d, 11.2Hz), 6.01 (1H, d, 11.2Hz), 5.32 (1H, m), 5.00 (1H, m), 4.43 (1H, m), 4.22 (1H, m), 2.82 (1H, dd, 11.8, 3.7Hz), 2.68 (1H, t, 6.0 Hz), 2.59 (1H, dd, 13.2, 3.5 Hz), 2.31 (1H, dd, 13.2, 6.5 Hz), 2.05-1.85 ( 5H, m), 1.31 (3H, s), 1.26 (3H, s), 0.94 (3H, d, 6.3Hz) and 0.55 (3H, s).

 MS: m / z at 414 (M +: 7), 396 (45), 378 (34), 269 (5), 251 (9), 195 (6), 181 (5), 171 (7), 169 ( 6), 161 (8), 159 (9), 157 (12), 155 (16), 152 (19), 134 (61), 105 (28), 91 (27), 81 (24), 71 ( 22), 55 (41) and 43 (100).

Example 19. Synthesis of epoxyketones 18'a, 18'b
To a solution of 0.096 g (0.34 mmol) of 17'a, 17'b in 8.0 ml of anhydrous dichloromethane is added 0.36 g (0.95 mmol, 2.8 equivalents) of pyridinium dichromate. (DCP) and a catalytic amount of pyridinium p-toluenesulfonate (PTSP) and the suspension is stirred for 4.5 hours at room temperature under argon.

10 ml of diethyl ether are added, stirring is continued for 5 minutes, the reaction mixture is filtered through a bed of
Celite / silica gel using ether and washed several times with ether the precipitated chromium salts and filtered. The combined filtrates are concentrated under reduced pressure and the residue is purified by HPLC on a 10 ml silica column using a 95/5 mixture of isooctane / acetone as eluent. 0.070 g (74%) of a mixture of diastereoisomers 18'a and 18'b are obtained in the form of an oil.

Rf (isooctane / acetone: 95/5): 0.16.

Spectral value of 18'a, 18'b
IR (KBr-film): 2,960 (F), 2,348 (F), 2,282 (F), 1,714 (F), 1,470, 1,379, 1,308, 1,246, 1,225, 1,057,943, , 913, 840 and 733 cm-1 H NMR (CDCl3, 360 MHz): 2.73 (1H, t, 3.5 Hz), 2.61 (2H, m), 2.44 (1H, dd, 11.7, 7.5 Hz), 2.31-2.16 (2H, m), 2.13 (1H, dm, 13.2Hz), 2.04-1.81 (3H, m), 1.71 (1H, m), 1.30 (2H, m), 1.09 (1H, ddd, 14.1, 10.8, 8.3 Hz), 1.04 + 1.02 (3H, 2 xd, 6.7 Hz), 0.87 + 0.85 (3H, 2 xs), 0.84 + 0.82 (3H, 2 xs) and 0.66 + 0.65 (3H, 2 xs) .

 MS: m / z at 278 (M +: 1), 248 (1), 193 (12), 178 (8), 163 (7), 149 (14), 135 (14), 124 (22), 111 ( 36), 95 (30), 81 (43), 69 (36) and 55 (100).

Example 20. Synthesis of 24 (S) -1-alpha; -hydroxy-24,25-epoxy-25,25-dinor-
23,23-dimethylvitamin D3 (30'a) and 24 (R) -24,25
epoxy-25,25-dinor-23,23-dimethyl-12-OH-vitamin D3 (30'b)
A solution of 0.085 g (0.146 mmol, 2.03 equivalents) of IV in 1.4 ml of anhydrous tetrahydrofuran is placed under an atmosphere of 1.1 bar of argon and 0.056 ml of a solution of n-butyllithium is added. 2.5 M in n-hexane (0.14 mmol). The dark red solution obtained is stirred for 30 minutes. 0.02 g (0.072 mmol) of the 18'a, 18'b ketones dissolved in 0.8 ml of anhydrous tetrahydrofuran are added dropwise. The mixture is stirred at -700C for 1.5 hours and then allowed to return to room temperature over a period of 2.5 hours. 2 to 3 drops of water are added to the still red solution and the bulk of solvents under a stream of argon. 2.0 ml of saturated sodium bicarbonate solution are added, followed by extraction several times with 2.0 ml of diethyl ether. The combined extracts are filtered through a bed of Merck Kieselgel 60 and the solvent is removed under reduced pressure. The residue is rapidly chromatographed on a column of
HPLC of 10 pine with 85/15 mixture of n-hexane / ethyl acetate as eluent. The oil obtained (mixture of 29'a and 29'b) is immediately taken up in 0.5 ml of anhydrous tetrahydrofuran, 0.025 ml of a 1 M solution of tetrabutylammonium fluoride (FTBA) in tetrahydrofuran is added and the solution is stirred for 30 hours at room temperature under argon in the dark. The solvent is removed under a stream of argon and the residue is chromatographed on Merck Kieselgel 60 with a 9/1 mixture of dichloromethane / methanol as eluent. Additional purification by HPLC (10 μm silica, 95/5 dichloromethane / methanol) provided 0.023 g (77%) of a mixture of the 30'a and 30'b isomeras as a glassy material.

Rf (dichloromethane / methanol: 9/1): 0.41.

Spectral value of 30'a, 30'b:
UV (MeOH)? Max = 263 nm.

IR (KBr-film): 384 (F), 2950 (F), 2250, 1642, 1444, 1378, 1054, 958, 910, 833, 800 and 735 cm1.

1H-NMR (CDCl3, 360 NHz): 6.37 (1H, d, 11.2Hz), 6.02 (1H, d, 11.2Hz), 5.32 (1H, brs), 4, 99 (1H, brs), 4.42 (1H, m), 4.22 (1H, m), 2.81 (1H, dd, 11.8, 3.8Hz), 2.75 (1H, m.p. dd, 4.0, 3.0 Hz), 2.61 (3H, m), 2.31 (1H, dd, 13.4, 6.4Hz), 2.05-1.87 (5H, m.p. ), 1.07 (1H, ddd, 14.1, 11.9, 8.3 Hz), (1.02 + 1.00 (3H, 2 xd, 6.5 Hz), 0.89 + 0, 87 (3H, 2 xs), 0.83 + 0.81 (3H, 2 xs) and 0.58 + 0.57 (3H, 2 xs).

 MS: m / z at 414 (M +: 7), 396 (64), 378 (36), 367 (6), 352 (5), 285 (6), 269 (7), 251 (10) 209 (10). ), 195 (9), 152 (27), 134 (83), 105 (38), 95 (27), 91 (34), 81 (31), 69 (51) and 55 (100).

Example 21. Synthesis of Ketone 20
From the tosylate 1c, the reaction with the lithian derivative obtained from the acetal of 3-butyne-2-one provides the acetal 19 according to the procedure of Uskokovic described for a similar product in ref. 32.

IR (KBr): 3475, 2935, 2867, 20717, 1675 cl.

The hydrolysis is carried out in aqueous dioxane in the presence of sulfuric acid. Ketone 20 has the following spectroscopic values
IR (KBr-film): 3475, 2935, 2867, 20720, 1675 cm-1.

1 H-NMR (360 MHz, CDCl 3): 4.09 (m, 1H), 2.41 (1H, dd, 17.2, 3.6Hz), 2.33 (3H, s), 2.21 ( 1H, dd, 17.2, 7.6 Hz), 1.05 (3H, d, 6.6 Hz), 0.93 (3H, s) ppm.

Example 22. Synthesis of epoxides 21a, 21b
A mixture of 131 mg (0.642 mmol) of trimethylsulfonium iodide, 54 mg (0.964 mmol) of potassium hydroxide powder and 1 ml of acetonitrile is stirred at 600 ° C. under nitrogen for 5 minutes. A solution of 50 mg of (0.160 mmol) in 1 ml of acetonitrile is added producing an orange color. The resulting mixture is stirred for 1 hour and 40 minutes. The color turns yellow. The mixture is filtered directly through a short column of silica gel eluting with 220 ml of EtOAc at 50 t in hexane.

Concentration gives a residue which is separated by HPLC (hexane / EtOAc: 8/2) to obtain 13 mg (30%) of 21a, 21b as an oil.

Rf (hexane / EtOAc: 8/2): 0.31.

Spectral values for 21a, 21b: IR (KBr-film): 3456 (F, broad), 3047 (f), 2240 (f), 1251 (F), 943 (F), 760 cm-1.

1 H-NMR (360 MHz, CDCl 3): 0.93 (s, 3H), 1.04 (d, 6.58 Hz, 3H), 1.54
(s, 3H), 2.02 (m, 1H), 2.25 (m, 1H), 2.72 (d, 5.55 Hz, 1H), 2.97 (d, 5.55 Hz, 1H). ), 4.08 (bs, 1H) ppm.

 MS: m / z 261 (1.7), 243 (2.1), 163 (10.3), 95 (40.2), 81 (60.3).

Example 23. Synthesis of epoxyketones 22a, 22b
A mixture of 25 mg (0.091 mmol) of 21a, 21b, 103 mg (0.274 mmol) of DCP and 2 ml of dichloromethane is stirred under nitrogen for 4 hours. The mixture is filtered directly through a short column of silica gel eluting with 200 ml of 25% EtOAc in hexane. Concentration gives a residue which is purified by HPLC (hexane / EtOAc: 8/2) to obtain 19 mg (76%) of 22a, 22b as an oil.

Rf (hexane / EtOAc: 8/2): 0.33.

Spectral values of 22a, 22b: IR (KBr-film): 239 (f), 1712 (F), 127, 857, 763 cm-1.

1 H-NMR (360 MHz, CDCl 3): 0.63 (s, 3H), 1.09 (d, 6.20 Hz, 3H), 1.54 (s, 3H), 2.47 (dd, 11, 61 Hz, 7.51 Hz, 1H), 2.73 (d, 5.55 Hz, 1H), 2.97 (d, 5.55 Hz, 1H) ppm.

Example 24. Synthesis of Vitamin D3 Derivatives 32a, 32b
To a stirred solution of 77 mg (0.132 mmol) of phosphine oxide IV in 1 ml of anhydrous THF under nitrogen at -800 ° C., 53 μl of a 2.5 M solution of n-BuLi in a mixture of hexanes, which provides a dark orange solution. The mixture is stirred under these conditions for 1 hour. 18 mg (0.066 mmol) of 22a, 22b in 0.8 ml of anhydrous THF are slowly added dropwise to the solution.

The mixture obtained is stirred at -800 ° C. for 2 hours. The solution is allowed to cool slowly to room temperature as it turns pale yellow and finally becomes almost colorless. The mixture is subjected directly to flash chromatography (hexane / EtOAc 9/1) to obtain a crude product which is purified by HPLC (hexane /
EtOAc: 18/1) to obtain 37 mg (88%) of 31a, 31b completely pure
in the form of an oil.

Rf (hexane / EtOAc: 9/1): 0.64.

A solution of 37 mg (0.058 mmol) is protected from light
31a, 31b and 700 111 of a 1M solution of 1 M (n-Bu) 4NF in THF
(0.70 mmol) in 1.5 ml of THF, and the mixture is stirred under nitrogen for
8 hours. The mixture is filtered directly on a short column of silica gel eluting with 100 ml of 8% CH3OH in CH2Cl2. By
concentration, a residue is obtained which is separated by HPLC (CH 2 Cl 2 /
CH3OH: 96/4) to obtain 19 mg (80%) of 20 pure as a
white solid.

Rf (CH2Cl2 / CH3OH: 9.5 / 0.5): 0.38
Spectral values for 32a, 32b: UV (CH3OH): #max = 262 nm.

IR (KBr-film): 304 (broad, F), 2339 (f), 1647 (broad), 1251, 1054 (F), 911, 863, 800, 737 cm-1.

1 H-NMR (360 MHz, CDCl 3): 0.54 (s, 3H), 1.06 (d, 6.51 Hz, 3H), 1.54.
(s, 3H), 2.28 (m, 2H), 2.59 (m, 1H), 2.73 (d, 5.56 Hz, 1H), 2.83 (m, 1H), 2.97 (d, 5.56 Hz, 1H), 4.22 (m, 1H), 4.42 (m, 1H), 4.99 (bs, 1H), 5.32 (bs, 1H), 6. , 01 (d, 11.25 Hz, 1H), 6.37 (d, 11.25 Hz, 1H) ppm.

MS: m / z 410 (M +: 16), 392 (28), 374 (25), 359 (3), 315 (3), 297
(4), 279 (3), 134 (100).

Example 25. Synthesis of Diol Ib
The diol la is oxidized by pyridinium dichromate (DCP) in the presence of pyridinium p-toluenesulfonate in dichloromethane.

The oxidation is not selective and a mixture of hydroxyketone, ketoaldehyde and hydroxyaldehyde 2a is obtained. After purification of the latter (Rf: 0.22, ethyl acetate / hexane: 1/1) on silica gel, it is treated with a catalytic amount of diazabicyclo-undecene in dichloromethane. After 3 hours, the mixture is treated with ether. The ethereal solution is washed with 2 ml of 5% hydrochloric acid. After drying over Na2SO4, filtration and concentration, a mixture of aldehydes 2a and 2b (respectively 36/64 according to H-RMH) is obtained. Rf (ether / hexane: 1/1): 0.28.On 101 mg (0.48 mmol) of this mixture was dissolved in 10 ml of methanol and treated at 0 ° C. with 90 mg (2.38 mmol) of borohydride. sodium. After 30 minutes, concentrate in vacuo and add ice and 20 ml of ether. After washing the organic phase with 1 ml of 5% hydrochloric acid and water, it is dried (Na 2 SO 4) and the residue obtained is purified by concentration in vacuo by chromatography on silica gel (benzene / hexane / ether: 3 / 2/5). 62 mg (0.293 mmol) of the isomer Ib having an Rf of 0.18 are thus obtained in addition to the la isomer (Rf: 0.16).

Spectral values of 2a: 1H-NMR (500 MHz, CDCl3): 9.57 (1H, d, 3.18Hz), 4.11 (1H, m), 1.10 (3H, d, 6.83Hz) ) and 0.98 (3H, s) ppm.

Spectral values of 2b: 9.53 (1H, d, 4.96Hz), 4.09 (1H, m), 1.02 (3H, d, 6.82Hz) and 0.95 (3H, s) ppm.

Spectral values of lb: 4.08 (1H, m), 3.72 (1H, dd, 3.5, 10.7Hz), 3.45 (1H, dd, 6.9, 10.6Hz), 0.955 (3H, s), 0.954 (3H, d, 6.6Hz) ppm.

EXAMPLE 26: Experimental Models for the Biological Evaluation 1) Study of the Differentiation of Leukemic Cells
The HL-60 human leukemia cells (promyelocyte line) are cultured in T-25 flasks at a density of 1.2 × 10 5 cells per ml of RPMI 1640 medium (containing 10% heat-inactivated fetal calf serum and antibiotics) and in the presence of increasing concentrations of 1 alpha, 25- (OH) 2D3 or analogs. The cells are then cultured for 4 days at 37 ° C. under an atmosphere of 5% CO2 in the air. the differentiation of promyelocytic cells into macrophages is evaluated by the reduction test of
NBT (salt of Tetrazolium Nitro Blue), according to the method of Ostrem et al [23].

The percentage of cells containing formazan granules (black) is determined by counting cells with a hematocytometer.

2) Study of the differentiation of human epidermal cells
The pharmacological property of cell differentiation is also studied on human epidermal cells or keratinocytes, in primary culture. Keratinocytes are isolated from skin fragments (biopsies, surgical resection), according to the method described by
Matsumoto et al [24]. The skin fragments are incubated overnight at 40C in the presence of a buffered saline solution (150 mM PBS, pH 7.4), containing 100 U of dispase per ml. The epidermis is then separated from the dermis and then treated for 10 minutes in the presence of a 0.25% trypsin solution, 0.02% EDTA, at room temperature. The reaction is stopped by addition of
PBS containing 10% calf serum. The cells are then washed twice by centrifugation, resuspended in the complete culture medium and then cultured at 37 ° C. and 5% CO 2 in air, in T-25 flasks. MCDB 153 modified (Gibco) serum-free and containing beef pituitary extract and epidermal growth factor [24] After 24 hours, the epidermal cells adhere to the support and will gradually multiply.

For the study of the biological activity of the compounds, the cells obtained after the second pass are cultured in multiwell plates (24 or 96 wells) at the cell density of 5 to 8 × 10 4 cells / cm 2. After 24 hours, increasing concentrations of 1 alpha, 25- (OH) 2D3 and analogs are added to the culture medium. After different incubation times, growth and cell differentiation are determined using the following evaluation parameters. (a) cell viability [MTT test or tetrasolium salt according to the protocol
from Bio-Rad; measurement of LDH] (b) total protein [BCA method or bicinchoninic acid from
Pierce]; (c) cell growth [incorporation of tritiated thymidine] (d) epidermal differentiation [differential staining of cytokeratins
Rhodanil Blue, cytochemical detection of keratin 67 k,
filaggrin and involucrine using monoclonal antibodies
specific (Biosoft, Biomedical Technologies)].

3) Effect on the proliferation of lymphocyte cells
This test determines the ability of a compound, in this case an analogue of vitamin D, to inhibit the proliferation (proliferation) of lymphocyte cells previously stimulated by phytohemagglutinin.

 The cells of the white line are isolated by centrifugation of human blood heparinized on Ficoll-Paque (buffy coat technique). The buffy coat cells are treated with phytohemagglutinin and then cultured in the presence of increasing concentrations of compounds and tritiated thymidine, according to a previously described protocol [25]. At the end of the incubation, cell-associated radioactivity is measured. Cellular proliferation is defined as the ratio of cell-associated radioactivity in the presence of compounds to that of control cells, expressed as a percentage.

4) Study of the antiproliferative effect on human tumor cells
Various tumor cell lines are used to determine the antitumor properties of vitamin D analogs. These include human cell lines derived from breast adenocarcinoma (MCF-7, T-47D), colon (CX1) , lung (LX1) or melanoma (MM-96).

 During the test, the cells are cultured in 96-well multiwell plates. The initial cell density is from 2 to 5,000 cells per well depending on the line under consideration, in order to maintain the cells in log phase of growth throughout the duration of the experiment. After 24 hours, the cells are incubated in the presence of increasing concentrations of vitamin D and its analogues for different periods of time.

At the end of each incubation, the protein concentration (Pierce BCA method), tritiated thymidine incorporation and cell viability (MTT and LDH assay) are determined. Its different parameters make it possible to evaluate the cell growth and the cytotoxic effect of the compounds. The antitumor activity is expressed as a percentage of growth inhibition relative to the control cells.

5) Calcemic effect in rickety chicken
The rickets chicken model is used to evaluate the pharmacological effect of vitamin D on phospho-calcium metabolism, particularly in the intestine (calcium absorption) and bone tissue (mineralization). It was to study in this model the calcemic effect of vitamin D [26].

 Root chickens are obtained by raising chicks from birth, in the absence of light and under a diet low in calcium. After three weeks, the animals are treated for 10 days with vitamin D or its analogues, with a daily intramuscular injection. At the end of the treatment, the animals are sacrificed; serum, intestine and bone tissue are removed. Serum and bone calcium content is measured by atomic absorption; serum osteocalcin and intestinal protein calbindin-28k, two vitamin D-dependent proteins are determined by radioimmunoassay RIA, using specific antibodies.

 The measured parameters reflect the phosphocalcic metabolism. Serum calcium and the presence of intestinal cabindin testify to the effect of vitamin D on the intestinal absorption of calcium. The calcium content of bone and serum osteocalcin is representative of mineralization and bone formation.

6) Study of in vitro differentiation on human osteosarcoma
The MG-63 cell line is derived from osteosarcoma of human origin and exhibits the characteristics of osteoblasts (bone matrix cells). The cells of this line are used to evaluate the hypercalcemic or osteocalcic effect of vitamin D on bone tissue.

 In this test, the cells are incubated in the presence of increasing concentrations of compounds. After 48 hours of incubation, the concentration of intracellular calcium (flame spectrometer) and osteocalcin (RIA) are determined. Osteocalcin is a specific protein produced by osteoblasts during bone formation; this parameter reflects well the stimulatory effect on the bone cells.

7) Study of the formation of plurinucleate cells from bone marrow in culture
At the bone level, vitamin D influences bone resorption and increases the number of osteoclastic cells. Different systems have been described to evaluate the activity of vitamin D on bone cells in vitro. A particularly effective system is to determine the formation of multinucleate cells from bone marrow culture under the inducing effect of vitamin D and its analogues.

The multinucleate cells formed under these conditions present all the functional and morphological characteristics of osteoclasts.

 The method used is that described by Ishizuka et al. [27].

Briefly, the bone marrow is taken from mouse femurs and resuspended in MEM (Minimum Essential Medium) culture medium containing 10% fetal calf serum, previously inactivated by heat. The cell suspension is then placed in 24-well multiwell plates at the rate of 106 cells per well (1 ml). The cells are incubated at 37 ° C. under an atmosphere of 5% CO2 in air After one day of culture, the culture medium is replaced by fresh complete medium (control culture) or medium containing different concentrations of vitamin. D and its analogues (test culture) The medium is renewed every three days.In the course of the culture, the number of multinucleate cells (> 3 nuclei / cell) is determined by counting with the aid of an inverted microscope. phase contrast At day 8, the cells are fixed with methanol and stained with Giemsa to allow the morphological study of the cells.

EXAMPLE 27 Biological Properties of Vitamin D Analogues According to the Invention
A) The epoxide function confers on the analog 1 alpha-hydroxy-vitamin D the characteristic properties of the active metabolite of vitamin D.

 For example, the biological activity of the epoxide derivatives of vitamin D and 1-alpha-hydroxy-vitamin D was compared in the induction test of HL-60 leukemia cell differentiation.

 In this test, cell proliferation is only weakly inhibited by l-alpha-OHD3. The 50% inhibitory effect (ED50) of 1 alpha-OHD3 is obtained for a high extracellular concentration of 3 x 10 6 M. The addition of an epoxide group to 1 alpha-OHD3, for example at position 25 as in the case of compound 24 (1 alpha-hydroxy 25,26-epoxy, vitamin D3) allows the inhibition and complete differentiation of leukemic cells, and for much lower concentrations. Thus, the biological effect is obtained at the concentration of 3 × 10 8 M, ie 100 times less.

 Thus, the presence of an epoxide function in the side chain of 1-alpha-hydroxy-vitamin D confers on it biological properties, in this case of cell differentiation, specific to the active metabolite of vitamin D hydroxylated in the side chain. (1 alpha, 25- (OH) 2D3).

B) The epoxidic analogues of vitamin D have clearly dissociated biological activities compared to the active natural metabolite of vitamin D, hydroxylated in position 25.

 By way of example, the biological activity of epoxide analogues is compared with that of 1 alpha, 25- (OH) 2 D 3 in in vitro tests, on epidermal (keratinocyte), osteoblastic and leukemic human cells, and in vitro. vivo in the rickety chicken model.

1. Differentiation of leukemic cells
In the HL-60 leukemia cell differentiation induction test, cell proliferation is remarkably inhibited by alpha, 25-dihydroxy vitamin D3 and epoxide analogues of vitamin D. The inhibitory effect of 50% of I alpha, 25- (OH) 2D3 is obtained for an extracellular concentration of 1.24 x 10M. The epoxide derivatives also show a remarkable inhibition of the proliferation of HL-60 cells. For example, the inhibitory concentration of compound 32 (1 alpha-hydroxy-23,24-didehydro-25,26-epoxy vitamin D3) is 1.34 x 10-8 M.

So, the cell differentiation property of vitamin
D is conserved by the epoxide analogues, characterized by the presence of an epoxide function in the side chain of 1 alpha-hydroxy-vitamin D and this even in the absence of the hydroxyl group at position 25.

2. Differentiation of human epidermal cells
The comparative effect of epoxidic analogues of 1 alpha-OHD3 on epidermal cell growth was studied on primary cultures of human keratinocytes.

 At the extracellular concentration of 10 7 M, the epoxide analogues tested so far inhibit the growth of at least 45% of the keratinocytes in culture. The 50% inhibitory effect of keratinocyte growth is obtained, for example, for extra cellular concentrations of 6.2 x 10 7 M and 2.8 x 10 7 M for the compounds (1 alpha hydroxy-24, 25 epoxy-vitamin D3) and 32 respectively. In the same test, the active metabolite of vitamin D, 1 alpha, 25- (OH) 2D3, has significantly less effect on epidermal cell growth with an ED50 of 3.0 x 10 6 M. An effect significant inhibitor of epoxidic analogues is already observed at a concentration of 10 8 M, whereas 1 alpha, 25- (OH) 2D3 shows only a marginal effect.For example, the compound 26a ((24S, 251) -1 alpha, 24-dihydroxy-25,26-epoxy-vitamin D3) produces an inhibition of the order of 35% to 10 8 M.

 The results obtained show the excellent inhibitory power of the epoxidic analogs on human keratinocytes in culture, and clearly superior to that of I alpha, 25- (OH) 2D3, for example by a factor of 5 and 10 respectively for the compounds (1 alpha hydroxy24,25-epoxy vitamin D3) and 32 (1 alpha hydroxy-23,24-didehydro, 25,26-epoxy vitamin D3).

3. Effect of differentiation in vitro on human osteosarcoma
Human osteoblastic cells MG-63, derived from an osteosarcoma, are incubated in the presence of different concentrations of 1 alpha, 25- (OH) 2D3 and epoxide analogues. After 48 hours, secretion of osteocalcin is measured in the culture medium. Under normal culture conditions, MG-63 cells produce little or no osteocalcin.

 1 alpha, 25- (OH) 2D3 rapidly induces osteocalcin secretion by cells (ED50 = 1.6 x 10 M); the optimal effect is obtained at the concentration of 10-9 M. The epoxidic analogues are clearly less active than 1 alpha, 25- (OH) 2D3. The biological activity of 50% of the epoxide analogues is therefore observed at much higher extracellular concentrations. For example, compound 28b (24R, 25S) -1-alpha, 24-dihydroxy-25,26-epoxy-vitamin D3) induces only 50% of maximum secretion of osteocalcin by MG-63 cells at the concentration 4.2 x 10 9 M.

 Thus, the osteoblast cell stimulation property of vitamin D is affected by the epoxide derivation of the 1 alpha-OHD3 side chain. The biological effect of the epoxide analogues is obtained at much higher concentrations (at least one e); at high concentrations, the analogs behave like 1 alpha, 25- (OH) 2D3. There is therefore a dissociation between the effects on the cells of bone origin, where the effect is diminished, and the other cells such as keratinocytes or leukemic cells where the effect is conserved or more often considerably increased.

4. Calcemic effect in rachitic chicken
The in vivo biological activity of vitamin D and its derivatives has been studied in the rickety chicken model. Serum concentrations of calcium and osteocalcin were determined after 10 days of treatment of rickets with 1 alpha, 25- (OH) 2D3 or epoxidic analogues of 1 alpha-OHD3.

 In the case of 1 alpha, 25- (OH) 2D3, the calcium concentration in the blood increases proportionally with the dose administered, reaching the normal values in non-rachitic chicken at the daily dose of 80 ng / kg. Serum calcium reflects the calcium absorption of the intestine induced by vitamin D. In the case of epoxide analogues, the pharmacological effect is particularly reduced. For example, no calcium resorption of the intestine was observed for the 26a derivative (24S, 25R) -1 alpha, 24-dihydroxy 25,26-epoxy-vitamin D3) at the daily dose of 160 ng / kg.

Osteocalcin is produced specifically by bone cells, and is an excellent parameter of bone metabolism. 1 alpha, 25- (OH) 2D3 significantly stimulates bone metabolism
The maximum effect on serum osteocalcin is obtained at a daily dose of 40 ng / kg. The epoxy derivatives show little or no pharmacological effects on the bone tissue. By way of example, compound 32 (1-alpha-hydroxy-23,24-didehydro-25,26-epoxy-vitamin D3) is totally inactive (tested up to 160 ng / kg) whereas compound 24 ( 24S, 25R) -1 alpha, 24-dihydroxy-25,26-epoxy-vitamin D3) has a marginal activity only at the concentration of 160 ng / kg.Thus the changes in the side chain of the 1 alpha-hydroxy- vitamin D, significantly affect the main pharmacological property of 1 alpha, 25-dihydroxy vitamin D, namely phospho-calcium metabolism.

The calcemic effect of analogues is marginal to nonexistent.

C) The biological properties of the epoxide analogues of vitamin D can be modulated by their respective isomers.

 In the case of the epoxidic analogs of 1-alpha-hydroxyvitamin D, different isomeric forms are possible both at the level of the epoxide function and at the level of the side chain. Also, the impact of isometry of epoxide analogues on biological properties has been studied. By way of example, compounds 26a and 28b have been compared in terms of their differentiation properties of epidermal cells and their antiproliferative effects on human tumor cells.

 At the level of the human epidermal cells, the compound 26a inhibits 50% of the keratinocyte growth at the extracellular concentration (ED 50) of 3.1 × 10 7 M. The compound 28b, for its part, is twice as active, with an ED50 of 6.4 x 10 7 M. At a concentration of 10 8 M, a significant inhibitory effect is obtained with compound 26a (+ 35%) while compound 28b shows only a marginal effect.

 With respect to the antiproliferative effect on human tumor cells, compound 26a inhibits the growth of nearly 50% of MCF-7 cells after 7 days of incubation at a concentration of 10 7 M.

At this same concentration, the antiproliferative effect of compound 28b is reduced by at least a factor of three.

 Thus the isomerism of the side chain of epoxide analogues of vitamin D, and particularly at the level of the epoxide function, is able to significantly influence their biological activities at the cellular level. These results also show the interest of considering pure isomeric forms of epoxide analogues rather than mixtures.

D) The biological activity of epoxidic analogues of 1 alpha-hydroxyvitamin D may be greater than that of 1 alpha, 25-dihydroxyvitamin D.

Among the interesting biological properties of vitamin
D and epoxide analogues, effects on differentiation of human epidermal cells on the one hand, and antiproliferative effects on MCF-7 tumor cells on the other hand, were considered. By way of example, compound 32 exhibits an excellent inhibitory effect on cell growth compared to that of the active metabolite of vitamin
D, 1 alpha, 25- (OH) 2D3.

 On human epidermal cells, compound 32 is found to be at least 10-fold more effective in differentiating keratinocytes than 1 alpha, 25- (OH) 2D3, with an ED50 of 2.8 x 10 7 M and 3.0, respectively. On the other hand, on cultured MCF-7 cells, the antiproliferative effect is also in favor of the epoxy analog. At the concentration of 10 8 M, the 1 alpha, 25- (OH) 2D3 is inactive whereas about 20, 6 cell inhibition is obtained in the case of the compound 32. The biological activity 50% of this analogue is observed at the extracellular concentration of 5.9 x 10 8 M.

 As illustrated with this epoxide analog, the addition of an epoxide function in the side chain of 1 alpha-hydroxy vitamin D is able to not only maintain the cellular biological properties of 1 alpha, 25-dihydroxy vitamin D (see B)), but also to increase certain characteristic cell properties of vitamin D.

E) General biological properties of epoxidic analogues of 1 alpha-hydroxy-vitamin D.

 Vitamin D analogs, characterized by the presence of an epoxide function at the side chain, have particularly interesting in vitro and in vivo biological properties. The epoxide function advantageously replaces the hydroxyl function characteristic of the active metabolite and vitamin D analogs. It confers particular biological properties, making it possible to distinguish notably the epoxide derivatives of l-alpha, 25- (OH) 2D3 and its major like. Thus, the epoxide function makes possible the dissociation between the calcemic effect and the other forms of biological activities.

 The epoxidic analogues of 1-alpha-hydroxy-vitamin D generally possess the characteristic cellular properties of vitamin D. These include the differentiation of leukemic and epidermal cells, the antiproliferative effect on cancer cells and leukocyte cells. . Epoxide analogues are particularly effective on epidermal cells and cancer cells; however, they only weakly stimulate osteocalcin secretion by cells of osteoblastic origin. With regard to phospho-calcium metabolism, the calcemic effect of the analogues is considerably reduced (marginal activity), or even non-existent in the rickety chicken model.

 Thus, the significant reduction in calcemic effect gives the epoxide analogs definite advantages over vitamin D or its active metabolite, including increasing the concentration of compound that can be administered without influencing phospho-calcium metabolism.

This dissociation of activity makes it possible, for example, to stimulate the differentiation of leukemic or epidermal cells without, however, inducing a toxic deleterious calcemic effect.

 The results obtained make it possible to envisage the therapeutic application of epoxy analogues in the treatment of cutaneous affections, such as psoriasis, secondary hyperparathyroidism (chronic renal disease), and certain cancers (leukemia, lymphoma, myelodisplastic syndrome, melanoma, breast, etc ...), or as immunomodulators (suppression of proliferation of T lymphocytes, differentiation of monocytes, etc ...), especially in autoimmune diseases, inflammatory processes and during transplantation of skin, marrow or organs.

REFERENCES
1. Reichel, H., Koeffler, HF, and Norman, AW (1989) New Engl. J. Med.

 320.980 to 991.

 2. Manolagas, S.C. (1987) Anticancer Res. 7, 625-638.

 3. Rigby, W.F.C. (1988) Immunol. Today 9, 54-58.

4. Delmez, J., Tindira, C., Grooms, P., Dusso, A. Windus, DW and
Slatopolsky, E. (1989) J. Clin. Invest. 83, 1349-1355.

5. Slatopolsky, E., Weerts, C., Thielan, J., Horst, R., Harter, H., and Martin,
KJ (1984) J. Clin. Invest. 74, 2136-2143.

6. Brown, AJ, Ritter, CR, Finch, JL, Morrissey, J., Martin, KJ,
Murayama, E., Nishii, Y., and Statopolsky, E. (1989) J. Clin. Invest. 84,
728-732.

7. Moritomo, S., Onishi, T., Imanaka, S., Yukawa, H., Kozuka, T., Kitano,
Y., Yoshikawa, K., and Kumahara, Y. (1986) Calcif. Tissue Int. 38
119-122.

 8. Smith, E.L., Pincus, S.H., Donovan, L., and Holick, M.F. (1988) J. Am.

 Acad. Dermatol. 19, 516-528.

 9. Kato, T., Rokugo, M., Terui, T., and Tagami, H. (1986) Br. J. Dermatol.

 115, 431-433.

10. Holick, M.F. (1989) Exp. Biol. Med. XX, 246-257.

11. Staberg, B., Roed-Peterson, J., and Menne, T. (1989) Acta Derm.

 Venereol. 69, 147-150.

12. Binderup, E. (1990) Drugs of the Future 15, 15-18.

13. Gallagher, JC, Jerpbak, CM, Jee, WSS, Johnson, KA, DeLuca, HF,
and Riggs, BL (1982) Proc. Natl. Acad. Sci. USA 79, 3325-3329.

14. Gallagher, J.C. and Goldgar, D. (1990) Ann. Intern. Med. 113, 649-655.

15. Lemire, J.M. and Archer, D.C. (1991) Eight Workshop on Vitamin D, P273.

16. Veyron, P., Pamphile, R., Binderup, L. and Touraine, JL (1991) Eight
Workshop on Vitamin D, P64.

17. Zhou, J.-Y., Norman, AW, Chen, DL, Sun, GW, Uskokovic, Mr. and
Koeffler, HP (1990) Proc. Natl. Acad. Sci. USA 87, 3929-3932.

18. Cunningham, D., Gilchrist, NL, Cowan, RA, Forrest, GJ, and McArdle,
CS (1985) Br. Med. J. 291, 1153-1155.

19. Koeffler, HP, Hirji, K., and Itri, L. (1985) Cancer Treat. Resp. 69
1399-1407.

20. Abe, J., Morikawa, M., Miyamoto, K., Kaiho, S., Fukushima, M., Miyaura,
C., Abe, E., Suda, T. and Nishii, Y. (1987) FEBS Letters. 226, 58-62.

21. Binderup, L. and Bramm, E. (1988) Biochem. Pharmacol. 37, 889-895.

22. Zou, JY, Norman, AW, Lubbert, M., Collins, ED, Uskokovic, MR, and
Koeffler, HP (1989) Blood. 74, 82-93.

23. Ostrem, VK, Tanaka, Y., Prahl, J., DeLuca, HF and Ikekawa, N. (1987)
Proc. Natl. Acad. Sci. USA 84, 2610-2614.

24. Matsumoto, K., Hashimoto, K., Kiyoki, M., Yamamoto, M. and Yoshikawa,
K. (1990) J. Dermatol. 17, 97-103.

25. Vanham, G., Van Baelen, H., Tan, BK, and Bouillon, R. (1988) J. Steroid
Biochem.29, 381-386.

26. Bouillon, R., Van Baelen, H. and De Moor, P. (1980) J. Steroid Biochem.

 13, 1029-1034.

27. Ishizuka, S., Kurihara, N., Hakeda, S., Maeda, N., Ikeda, K., Kumegawa,
M., and Norman, AW (1988) Endocrinol. 123, 781-786.

Lythgoe B., Moran T., Nambudiry M., Tideswell J., Wright P .;
3. Chem. Soc., Perkin 2, 590-595 (1978).

Baggiolini E., Lacobelli J., Hennessy B., Uskokovic M .;
J. Am. Chem. Soc. 104, 2945-2948 (1982).

Partridge J., Faber S., Uskokovic M .;
Helv. Chim. Acta, 57, 764-771 (1974).

Lythgoe B., Roberts D., Waterhouse I .;
J. Chem. Soc. Perkin 1, 2608-2612 (1977).

32 Barrack SA, Gibbs RA, Okamura WH;
J. Org. Chem. 53, 1790-1976 (1988).

33 Gao Y., Hanson RM, Klunder JM, SY Ko, Masamune H., Sharpless
KB; J. Am. Chem. Soc. 109, 5765-5780 (1987).

Claims (12)

 1. Compounds derived from vitamin D or an analogue thereof having in particular a side chain grafted in position 17 on the D ring of vitamin D, characterized in that they comprise an epoxide group grafted onto said side chain.  2. Compounds derived from vitamin D or an analogue thereof having a side chain grafted at position 17 on the ring D, said side chain comprising an epoxide group, corresponding to the formula

 in which - V represents a residue of vitamin D or one of its analogues whose  position 17 is vacant - X, grafted in position 17 of V, represents a hydrocarbon chain,  in particular alkyl, optionally from 0 to 15 carbon atoms  substituted or modified, in particular may include, in one or  multiple positions, group (s)  . hydroxyl, methyl, ethyl, halogen, preferably fluorine,  .ester, especially a group RlCOO with R1 which represents an alkyl  or C1-C7 linear or branched, saturated or unsaturated alkoxy,  optionally substituted in particular with one or more hydroxyl group (s)  or halogen, preferably fluorine,  . ether, especially a group R1-O with R1 which represents an alkyl  or C1-C7 linear or branched, saturated or unsaturated alkoxy,  optionally substituted with one or more hydroxy or halogen groups,  . oxo in keto form,  . a ring or heterocycle, in particular saturated or unsaturated cycloalkyl,  aromatic or heteroaromatic that may carry all the groups and  modifications mentioned above, and / or  - said X chain may comprise instead of one or more of its  carbon atoms, an oxygen, nitrogen or sulfur atom, - said chain X being unsaturated, with one or more double or triple carbon-carbon bonds, this unsaturated chain being able to carry all the groups and modifications mentioned above, and - said chain and the different groups on the chain that can adopt all isomeric forms, - the epoxy group

 which can be grafted on any one of the 15 carbon atoms of X, in particular at its end, an epoxide group in which  . R1, R2 and R3, which may be the same or different, represent  a hydrogen, a linear or branched, saturated or unsaturated C1-C10 alkyl group optionally substituted with one or more halogen, hydroxy or cycloalkyl groups, also optionally substituted with halogen or hydroxy groups;  . R1 and R2 can be part of the same cycle, such as carbocycle or  heterocycle, and in this case R3 has the same meaning as above  .R2 and R3 can be part of the same cycle, such as carbocycle or  heterocycle, and in this case R1 has the same meaning as above  . the different isomeric forms at the epoxide level being possible.  3. Compounds according to claim 2, characterized in that they correspond to the formula

  wherein X, R1 to R3 have the meanings given in claim 1 and A represents a hydrogen, a methyl or methylene group CH2

 represents a single or double bond, Y represents H or OH or an ester group, in particular R 1 COO, or ether, in particular R 1 O, with R 1 which has the meaning given in claim 1.  4. Compound according to claim 2 or 3, characterized in that X represents an alkyl chain of 0 to 6 carbon atoms, one carbon atom may be replaced by an oxygen atom and optionally substituted, in particular with one or more methyl hydroxyl and / or ether groups, in particular with an R1-O group, and X being unsaturated with a carbon-carbon double or triple bond, the epoxy group

 being grafted at the end of X, and R1, R2 and R3 represent a hydrogen, a hydroxyl, an alkyl group such as methyl or ethyl or hydroxyalkyl.  5. Compounds according to itune of claims 2 to 4, characterized in that they correspond to the formula

  in which Z represents a saturated or unsaturated alkyl chain of 0 to 3 carbon atoms, optionally substituted by a hydroxy, an alkyl such as methyl or ethyl on one or more of said carbon atoms, the epoxide group being grafted to the end of Z.  6. Compounds according to claim 5, characterized in that they correspond to the isomeric formulas IIa or IIb

 with  R1 R2 R3 Z  CH3HH -CH2-CH2  CH3HH -CH2-CHOH-  H CH3 CH3 -CH2  H H H -C (CH 3) 2  CH3 H H -C-C  7. Process for the preparation of a compound according to one of the preceding claims, characterized in that the resulting compound is reacted with a compound whose basic structural skeleton formula IV

 and n-butyllithium with a compound whose structural skeleton has formula III

  in which the reactive functions grafted onto said skeletons of III and IV are optionally protected and X, R1, R2, R3, the reactive functions of which are optionally protected, have the meanings given in claims 1 to 5, and then the said reactive functions, in particular of X, R1, R2, R3, are optionally deprotected; and hydroxyl in positions 1 and 3.  8. As a medicament, a compound according to one of claims 1 to 6.  9. Compound according to one of claims 1 to 6 for the implementation of a method of treatment and / or prophylaxis of cancer, including leukemias, lymphomas, myelodisplastic syndromes, melanomas, breast cancers, lung and colon, as well as their metastases.  10. Compound according to one of claims 1 to 6 for the implementation of a method of treatment and / or prophylaxis of psoriasis and dyskeratosis.  He. Compound according to one of claims 1 to 6 for use as an immunomodulator for preventing rejection of grafts, in use alone or in combination with other compounds such as cyclosporine or FK 506.  12. Compound according to one of claims 1 to 6 for the implementation of a method of treatment and / or prophylaxis of autoimmune diseases.  i3. Compound according to one of claims 1 to 6 for the implementation of a method of treatment and / or prophylaxis of osteoporosis.  14. Compound according to one of claims 1 to 6 for the implementation of a method of treatment and / or prophylaxis of hyperparthyroidie including secondary and renal failure.