IE70239B1 - Side-chain homologous vitamin D derivatives process for their production pharmaceutical preparations containing these derivatives and their use as pharmaceutical agents - Google Patents

Abstract

The description relates to novel side-chain-homologous vitamin D derivatives of formula (I), in which R<1>, R<2>, R<3>, R<4>, R<5> and R<6> have the significance given in the description, B and D are either a hydrogen atom or together a second bond (E-configuration double bond) and either A is a direct bond between the carbon atoms 20 and 22 and X is an alkyloxy radical -(CH2)nO- with n = 1 to 3 or A is a methylene bridge (-CH2-) between the carbon atoms 20 and 22 and X is an alkylene radical -(CH2)n- or an alkylenoxy radical -(CH2)nO- with n = 1 to 3, or if A is a direct bond and B and D together are a second bond, (a) is one of the radicals (b) , -(CH2)2-= or -(CH2)2-=, and a process for their production, pharmaceutical preparations containing this compound and its use in making medicaments. The new compounds have proliferation-inhibiting and cell-differentiating effects.

Description

The present invention relates to side-chain homologues of vitamin D derivatives of the formula I wherein 5 R- is a hydrogen atom, a hydroxy group or an acyloxy group having from 1 to 9 carbon atoms, R2 is a hydrogen atom or an acyl group having from i to 9 carbon atoms, R3 or R4 is a hydroxy group or an acyloxy group having 510 from 1 to 9 carbon atoms and the respective other substituent is a hydrogen atom, or R3 and R4 together represent an oxygen atom, R5 and R® each independently of the other is a linear or branched alkyl radical having up to 5 carbon atoms, a i5 trif luoromethyl group or, together, represent a saturated, unsaturated or aromatic carbocyclic or, with the inclusion of 1 or 2 N-, O or S-atoms, heterocyclic 3-, 4-, 5- or 6-membered ring formed with the tertiary carbon atom, b and D either each represents a hydrogen atom or together represent a second bond (E-configured double bond) and either A is a direct bond between carbon atoms 20 and 22 and X is an alkvleneoxv radial ~(CH2)nO~ wherein n = 1 to 3 or A is a methylene bridge (-CH2-) between carbon atoms 20 and 22 and X is an alkylene radical -(CH2)n- or an alkyleneoxy radical -(CH2)aO- wherein n = 1 to 3 or. when A is a direct bond and 3 and D together represent a second bond,, -X-C represents one of the radicals \R6 -CH2-O~CH2=<^] , -(CH2)2-= or ~(CH2)2-=, and to a process for the manufacture thereof, to pharmaceutical preparations containing those compounds and to ng the use thereof for the manufacture of medicaments.

The acyloxy and acyl groups possible for the radicals R1 and R2 and within the radicals R3 and R4 are derived especially from saturated carboxylic acids or also from benzoic acid. Other suitable acyl radicals in R1, R2, US R3, r4 include those which are cyclic, acyclic, carbocyclic or heterocyclic - all of which may also be unsaturated. Preferred radicals are derived from C3- to Cg·, preferably C2~ to C5-, alkanecarboxylic acids, such as, for example, acetyl-, propionyl-, butyryl-.

If R5 and R6 form together with the tertiary carbon atom a saturated carbocyclic ring, then it will be especially a cyclopropyl or cyclohexyl ring. Suitable alkyl groups for R5 and Rs are especially those having from 1 to 5 carbon atoms, which may be straight-chain or branched.

Examples are the methyl, ethyl, propyl and tert.-butyl groups.

Preferred according to the present invention are sidechain homologues of vitamin D derivatives of the general formula I wherein R1, R3 or R4 is a hydroxy group or R5 and R6 represent a methyl group or, together with the tertiary carbon atom, a cyclopropyl ring, R2 is a hydrogen atom and n is 1 or 2.

Between carbon atoms 22 and 23 (when A represents a direct bond) or between carbon atoms 23 and 24 (when A represents a methylene group), there is preferably a double bond. The following compounds are especially preferred: HO 24- (1(R)-hydroxy"4-methylpentyl) -9,10~secochola-5Z, 7E, (19),23E-tetraene-l(S),3(R)-diol, 24- (1 (S)-hydroxy-4-methylpentyl )-9, lO-secochola-5Z, 7E, 10(19),23E-tetraene~X(S),3(R)-diol? 24- (1(R)-hydroxy-3-methylbutyl) -9, l0-secochola~5Z, 7E, 55 10(19) „23S-tetraene-l(S) ^(RJ-diol, 24- (1 (S) -hydroxw-s-methylbutyl) -9, io-secochoXa~5Z, 7E, 10(19),23E-tetraene-l(S)„3(R)-dioX, 24-( 1(R)-hydroxy-3-methylbutyl)-9 c, l0-secochola-5Z ,7E,10(19)-triene-l(S)e3(R)-diol, 24 - (1 (S) -hydroxy-3-methyIbutyl )-9 s iO-secochoXa-5Z, 7E, 10(19)-triene~l(S)„3(R)-diol, 24-( l(R)-hydroxy-3"isopropoxypropyl )-9, X0-secochola~ 5Z,7E„10(19)e23E-tetraene-l(S)„3(R)-diol, 24-( l(S)-hydroxy-3-isopropoxypropyl)-9 , 10-secochola25 5Z,7E,10(19)„23E"tetraene-l(S),3(R)-diol„ 24-isopropoxymethyl-9,10-secochola-5Z, 7E1.10(19), 22Ξtetraene-1(S),3(R),24(R)-triol, 24-isopropoxymefchyl-9,10-secochola-5Z , 7Ξt 10 (19)»22Etetraene-i(S),3(R),24(S)-triol, 24-(2~isopropoxyethyl)-9,10-secochola-5Z,7E,10(19),22Etetraene-l(S),3(R) £, 24(R)-triol, 24-(2-isopropoxyethvl)-9,10~secochola-5Z, 7Ξ, 10(19), 22E~ tetraene-l(S),3(R),24(S)-trio!, , 27-cyclO"24a, 24b-dihomo-9,10-secocholesta5Z,7E„10(19), 23E-tetraene-l (S),3(R),24a(R) -triol, , 27"cyclo-24a, 24b-dihomo-9, 10-secocholesta-5Z ,73,10(19),23E-tetraene-l(S) , 3 (R), 24a(S)-triol.

Natural vitamins D2δη<^ θ3 (cf. general formula V) are themselves biologically inactive and are not converted into their biologically active metabolites until they have been hydroxylated in the 25-position in the liver or in the 1-position in the kidneys. The effects of vitamins D2 and D3 is to stabilise the plasma Ca++ and plasma phosphate levels? they counteract a fall in the plasma Ca^ level. ergocalciferol: Re=R^=H, Rc=CH3 vitamin D2 double bond C-22/23 cholecalciferol: Ra=R^=Rc=H vitamin D3 -hvdroxycholecalciferol: Ra=Rc=H, R^=OH Ια-hydroxycholecalciferol: Ra=OH, R^=RC=H 1g,25-dihydroxycholecalciferol: Ra=R'°=0Ht, RC=H calcitriol In addition to their pronounced effect on calcium and phosphate metabolism, vitamins 02 and D3 and their synthetic derivatives also have proliferation-inhibiting and cell-differentiating effects (H.F. De Luca, The Metabolism and Function of vitamin D in Biochemistry of Steroid Hormones, ed. H.L.J. Makin, 2nd Edition, Slackwell Scientific Publications 1984, pages 71-115).

When using vitamin D, however, overdosage phenomena may occur (hypercalcaemia).

Ic-cholecalciferols hydroxylated in the 24~position are already disclosed in DS-A.S 25 25 981; they have a lower toxicity than the corresponding non-hydroxylated lG-cholecalciferol. The hydroxylated compounds exhibit a selective activation of intestinal calcium absorption and a weaker bone absorption action than lc-cholecalci~ ferol. The 24-hydroxy-vitamin D analogues described in 1,0 International Patent Application WO 87/00834 can be used for the treatment of disorders caused by abnormal cell proliferation and/or cell differentiation in humans and animals.

A dissociation of the properties bone absorption activity J5 and HL 60 cell differentiation has already been mentioned recently for various 1,25-dihydroxy-homo-vitamin 9 derivatives by De Luca. The bone absorption activity in vitro is in that study a direct measure of the calcium mobilisation in vivo..

It has now been found that the side-chain homologues of vitamin D derivatives of the general formula I according to the invention surprisingly have a more advantageous spectrum of action than the vitamin 9 derivative calcitriol (lc?,,25-dihvdroxycholecalciferol). While the effects on calcium and phosphate metabolism are distinctly weaker (reduction of the side-effects caused by overdosage or by the high dosage required), the proliferation-inhibiting and cell-differentiating actions are almost completely retained (dissociation).

The vitamin 9 activity of the compounds according to the invention is determined by means of the calcitriol receptor test. It is carried out using a specific receptor protein from the intestine of rachitic hens. Receptor-containing binding protein is incubated for one hour in a test tube with 3H-ca.lcitrioI (0.5 ng/ml) in a reaction volume of 0.575 ml in the absence and in the presence of the test substances. A charcoal-dextran absorption is carried out to separate free and receptorbound calcitriol. For that purpose.,, 200 μΐ of a charcoal-dextran suspension are added to each test tube and the batch is then incubated at 22‘c for 30 minutes. The 110 samples are then centrifuged at 1500 x g for 10 minutes at 4’C. The supernatant is decanted and,, after being equilibrated for approximately i hour in Atom Light, is measured in a B-counter. The competition curves obtained with various concentrations of the test substance and of 15 the reference substance (unlabelled calcitriol) with a constant concentration of the comparison substance (3Hcalcitriol) are set in relation to one another and a competition factor (CF) is determined.

This is defined as the ratio of the concentrations of the particular test substance and the reference substance that are required for 50 % competition: concentration of test substance at 50 % competition CF = —-—--concentration of reference substance at 50 % competition 25 In accordance with that equation, 24- (l-hydroxy-3-mefchylbutyl) -9,10-secochola-5Z, 7E, ~ (19) ,23E"tetraene-l(S) ,3(R)-dioI (compound A) has a CF value of 2.0 and 24- (I-hydroxy-3-methy Ibuty 1) -9 g 1 Q-secochola-52, 7E, 30 10(19),23E-tetraene~l(S),3(S)-diol (compound B) has a CF value of 3.6.

In order to determine the antiproliferative potency of the compounds according to the invention, the test described below is carried out using compounds A and 3 as representative test substances: Keratinocytes of new-born mice are prepared and cultured 5 in a modified form of the method of Yuspa, S. and Harris, C.C., Altered differentiation of mouse epidermal ceils treated with retinyl acetate in vitro, Exp. Cell Res. 3S: 95-105, 1974. 110 Neonatal NMRI mice of both sexes are sacrificed by decapitation, and the skin is removed , washed in an antibiotic-antimycotic solution and incubated dermal side down In Dispas© II solution (1.2 U/ml in tissue culture medium M199 + 25 mmol/1 of HEPES + 15 % foetal calf S5 serum (FCS) + 50 u/ml of penicillin/streptomycin (P/S) (preparation medium, PM) at 4’C overnight. The epidermis Is removed and, by trypsination, a single-cell suspension Is prepared. After centrifugation, the cell sediment is re-suspended and, after staining with trypan blue, the 2© number of live small round cells is determined and the cells are sown at a density of 4xl05 cells/cm2 in tissue culture medium (M199 + 15 % PCS + 50 U/ml P/s) in Primaria 24-well plates. After incubation for 24 hours at 37*c, the cells are washed with phosphate-buffered saline (PBS) and incubated at 32.5*C for a further hours in serum-free tissue culture medium (M199 + U/ml P/S + 0.5 % ethanol) with and without test substances. 0.4 μ€ϊ/50μΧ 3H-raefchylthymidine (40 Ci/mmol) is then added. After 4 hours, the medium is 3© drawn off and the reaction is stopped by the addition of 500 μΐ of ice-cold 10 % trichloroacetic acid (TCA). The cells are washed with TCA and PBS, lysed by incubation in a proteinase K solution (10 mmol/1 Tris-HCl, 10 mmol/1 EDTA, 10 mraol/1 NaCl, 0.2 % Triton-X 100, pH 8.0, 50 pg/ml protein kinase K) and the lysate is clarified by centrifugation. In the supernatant, the radioactivity is determined by scintillation photometry and, after specific staining of the DMA with diamidinophenylindole (DAPI), the DMA concentration is determined by fluorescence photometry.

According to those measurements, calcitriol and compounds A and 3 inhibit the incorporation of 3H-thymidine into DNA in a dose-dependent manner, with the following IC50 values: calcitriol compound A compound .3 χ 10"9 mol/1 1 x IO8 mol/1 3.2 χ IO™9 mol/1 There is virtually no difference in the differentiationstimulating activity of calcitriol and the compounds according to the invention 26.27- cyclo-24a, 24b-dihomo-9,10-secocholesta-5Z, 73,10(19),233-tetraene-l(S),3(R),24a(R)-triol (compound C) and 26.27- cvclo-24a,24b-dihomo-9,10-secocholesta-5Z,73," 10(19),23S-tetraene-l(S) ,3(R) ,24a(S)-triol (compound 9).

It is known from the literature (Hangelsdorf, D.J. et al., J. Cell. Biol. 93: 391-398 (1984)) that the treatment of human leukaemia cells (promyelocyte cell line HL 60) in vitro with calcitriol induces differentiation of the cells to macrophages.

In order to quantify the differentiation-stimulating activity of calcitriol analogues, the test described below is carried out: HL 60 cells are cultured in tissue culture medium (RPMI - 10 § foetal calf serum) at 37 "C in an atmosphere of 5 S CO? in air.

For testing the substances, the cells are centrifuged off and 2.8 x 105 cells/ml are taken up in phenol-red-free tissue culture medium. The test substances are dissolved 5 in ethanol and diluted to the desired concentration with tissue culture medium without phenol red. The dilution stages are mixed with the cell suspension in a ratio of 1:10 and 100 μΐ of the cell suspension combined with test substance are pipetted into each well of a SS-well plate. 80 For control purposes, the solvent is added to a cell suspension analogously.

After incubation for 96 hours at 37'c in 5 % CO? in air, 100 μΐ of a MBT-TPA solution (nitro blue tetrazolium (HBT), final concentration in the batch 1 mg/ml, tetradecanoylphorbolmyristate-13-acetate (TPA), final concentration in the batch 2 x 107 mol/1) are pipetted into the cell suspension in each well of the 96-well plate.

By incubation for 2 hours at 37 C in 5 % C02 in air, because of the freeing of intracellular oxygen radicals, stimulated by TPA, in the cells differentiating to macrophages K3T is reduced to insoluble formazan.

To conclude the reaction, the wells of the 96-well plate are evacuated and the adherent cells are fixed by adding methanol and, after being fixed, are dried.

In order to dissolve the intracellular formazan crystals formed, 100 μΐ of potassium hydroxide (2 val/1) and 100 μΐ of dimethyIsulphoxide are pipetted into each well and the wells are treated with ultrasound for 1 minute.

The concentration of formazan is measured by spectrophotometry at 650 nm.

The quantity indicative of the induction of differentiation of the HL SO cells to macrophages is the concentration of formazan formed. The relative activity of the test substance is found from the ratio ED50 test sub5 stance / ED50 calcitriol.

In accordance with that ratio, calcitriol, compound C and compound D have ED50 values of 18 x 1O9 mol/1, 2.2 x ΐθ"θ mol/1 and 2.5 x 10~s mol/1, respectively.

Owing to the reduced risk of hypercalcaemia, the substanJO ces according to the invention are especially suitable for th® manufacture of medicaments for the treatment of diseases characterised by hyperproliferation., for example hyperproliferative skin diseases (psoriasis) and malignant tumours (leukaemia, colon carcinoma, mammary 15 carcinoma). In an especially preferred form of the invention., the presence of calcitriol receptors in the target organ is ascertained before the treatment.

The present invention accordingly relates to pharmaceutical preparations containing at least one compound according to the general formula I together with a pharmaceutically acceptable carrier. The compounds may be formulated as solutions in pharmaceutically acceptable solvents or as emulsions, suspensions or dispersions in suitable pharmaceutical solvents or carriers, or as pills, tablets or capsules which, in a manner known per se, contain solid carriers. For topical application, the compounds are advantageously formulated as creams or ointments or in a similar medicament form suitable for topical application. Each such formulation may also 30 contain other pharmaceutically acceptable and non-toxic auxiliaries, such as, for example,, stabilisers, antioxidants, binders, dyes, emulsifiers or taste correc11 tives. The compounds are advantageously administered by injection or intravenous infusion of suitable sterile solutions, or as an oral dosage form v,j.a the alimentary canal or topically in the form of creams, ointments, 5 lotions or suitable transdermal patches, as is described in EP-A-0 387 077.

The daily dose is 0.1 pg/patient/day - 1000 μο (1 rag)/patient/day, preferably 10 1.0 ug/patient/day - 500 p,g/patient/day.

The compounds according to the invention are generally administered analogously to the administration of the known agent Mcalcipotriol" for the treatment of psoriasis .

D5 The invention further relates to the use of the compounds according to formula I for the manufacture of medicaments .

The manufacture of the side-chain homologues of vitamin D derivatives of the formula I is carried out according to 2© the invention as follows: a compound of the general formula IV (IV), wherein R1* is a hydrogen atom or a protected hydroxy group and R2' is a hydroxy-protecting group and A, X and R5 and Rs have the meanings given in formula I, if desired after selective hydrogenation of the double bond in the side chain to form a compound of the general formula IVa wherein R1, R2\ A, X and R5 and R6 have the meanings "0 given in formula IV, and if desired after reduction of the carbonyl function and, optionally, after separation of the mixture of epimeric hydroxy compounds of the general formulae Ilia and mb formed by the reduction D UHal s d-OH (X1X to > z θ - pt-j wherein R-, R2,, A, X and R5 and Rs have the meanings given in formula iv and 3 and D have the meanings given in formula Σ j, is converted by irradiation with ultraviolet light, with the stereoisomerism at the 5,6-double bond being reversed, into a compound of the general formula II wherein R1* , R2\ A, 3, D, X and R5 and Rs have the meanings given in formula Illa/IIIb, which is then converted by removal of any hydroxyprotecting groups and, optionally, by partial or complete esterification of the hydroxy groups, into a compound of the general formula 1.

The reduction of the side-chain carbonyl function in the compound of the general formula IV is carried out, for 5 example, with cerium(XII) chloride/sodium foorohydride in a polar solvent. In the reduction, both the R- and the S-hydroxv isomer of the general formula Ilia and Illb, respectively, is formed. The two isomers can be separated by chromatography.

I© If desired, the double bond in the side chain may be selectively hydrogenated before th~ reduction of the carbonyl function. A suitable hydrogenation agent is, inter alia, lithium tri-terfc.-butoxyaluminium hydride in a polar solvent.

The subsequent conversion of a compound of the general formula IlXa/IIIb into a compound of the general formula II is carried out, for example, by irradiation with ultraviolet light in the presence of a so-called ’’triplet sensitiser88. For the purposes of the present invention, anthracene is used as the triplet sensitiser. By splitting the pi bond of the 5,5-double bond, rotation of the A-ring through 180' about the 5,6-double bond and reestablishment of the 5,5-double bond, the stereoisomerism at the 5,5-double bond is reversed.

Subsequently, any hydroxy-protecting groups present are removed, preferably with the use of tetra-n-butylammonium fluoride, and, if desired, the free hydroxy group are. partially or completely esterified by conventional methods using the corresponding carboxylic acid halide (halide = chloride, bromide) or carboxylic acid anhydride.

Preparation of the starting materials 1. 1(S),3(R)-bis-(tert„-butyldimethylsilyloxy)-20(S)formyl-9,10-secopregna-5S,7E,l0(19)-triene 1: The preparation of 1 is carried out in accordance with m.J. Calverley, Tetrahedron. 43, 4609 (1987): see also International Patent Application WO 87/00834. The preparation of the starting compound wherein R1# is a hydrogen atom is also described therein. 2. 1(S)e3(R) bis-(tert.-butyIdimethylsilyloxy)-20(R) SO methyl-9,10-secopregna-5E,73,10(19) -trxene-21-carbaldehyde 2.: The aldehyde 2. is prepared by a new process. a. A solution of 15.57 g of diethylphosphonoethoxyacetic acid ethyl ester (prepared in accordance i5 with W. Grell and H. Machleidt, Liebigs Ann. Chem. 699 „ 53 (1966)) in 200 ml of THF is added dropwise at 25 C to a suspension of 1.8 g of sodium hydride (80 % in oil) in 70 ml of absolute THE. When the addition is complete, stirring is carried out for a further 90 minutes at 60C, the reaction solution is cooled again to 25C and a solution of 6.2 g of in 70 ml of THF is added dropwise thereto. The reaction solution is then stirred under reflux for hours and, when cool, is poured into water and extracted with ethyl acetate. After drying (Na2SO4) and concentration, the resulting crude product is chromatographed on silica gel with hexane/ethyl acetate. The main fraction yields .2 g of l(S) ,3(R)-bis-(tert.-butyldimethylsilyl3© oxy)-2 3"(ethoxv-9,I0-secochola™5E,73,10(19)tetraenoic-24-acid ethyl ester in the form of an oily mixture of the C-22 double bond isomers. b. 5.2 g of the product obtained in a. are dissolved in 120 ml of toluene and, at 0Ce 20 ml of a 20 % solution of diisobutylaluminium hydride in toluene are added thereto. After 30 minutes at 0°C, the 5 reaction solution is cautiously poured into NH«C1 solution and extracted with ethyl acetate. After customary working up,, 4.88 g of l(S) ,3(R)-bis (tert."buty1 d ime thy. 1 s i 1 y 1 oxy )-2 3-ethoxy-9,10~ secochola-SE,7E, 10( 19) „22-tetraen-24~ol are HO obtained in the form of a colourless oily isomeric mixture which is used in the next step without further purification. c. The compound prepared in b. (4.88 g) is stirred in a mixture of 55 ml of dichloromethane and 55 ml of 115 70 % strength aqueous acetic acid at room temperature for 4 hours. The reaction mixture is then neutralised by the addition of NH3 solution and extracted with dlchloromethane. The crude product is chromatographed on silica gel with hexane/ethyl acetate to yield 2 02 g of l(S) ,3(R)-bis~(tert„butyldimethylsilyloxy )-24-hydroxy~9,10-secochola5E 7Z,10(lS) ;rien-23 one S in the form of a colourless oil.

(CDC13): 6=0.01 ppm (s, 12H, Si-CH3), 0-52 (s, 3H, H 18),, 0.81 and 0.84 (s, each 9H, Si-tbutyl), 0.90 (d, J = 7 Hz, 3H, H-2X)„ 3.09 (t4, J = Hz, 1H, OH), 4.10 (dd, 1H, H~24), 4.16 (m, 1H, H3), 4.21 (dd, 1H, H"24), 4.39 (ffi, 1H, H-1), 4.88, 4.93 (s, each 1H, H-19), 5.77, 5.39 (d, J = 11 Hz, each 1H, H~6, H-7). d. The product (2.02 g) obtained in c. is dissolved in 25 ml of methanol and. 25 ml of THF and, at 0*C, 300 mg of sodium borohydride are added thereto.

The reaction mixture is stirred at OC for 1.5 hours, then poured into NH4C1 solution and extracted with ethyl acetate to yield 1.75 g of 1(5),3(R)-bis-(tert.-butyldimethylsilyloxy)-9,105 secochola-5S,7E,10(19)-trien-23,24-diol 6 in the form of a colourless oily mixture of the 23-epimers, which is used in the next reaction in that form. e. 1.75 g of the product obtained in d. are dissolved in 40 ml of toluene and, while cooling with icewater, 1.23 g of lead tetraacetate are added in portions. Stirring is carried out for 30 minutes, a further 1.0 g of Pb(OAc)4 is added and stirring is carried out for a further 15 minutes at from +5 85 to +10"C.

For working up, MaHCO3 solution is added, the resulting suspension is filtered over Celite and the filtrate is extracted with ethyl acetate. The crude product is chromatographed on silica gel with hexane/ethyl acetate. Crystallisation of the main fraction from ethanol yields 560 mg of 1(S),3(R)bis- (tert. -butyldimethylsilyloxy) -20 (R) -methyl9,, 10-secopregna-5S,7E, 10(l9)-triene-2!-carbaldehyde having a melting point of 101-104°C. Reaction of the aldehyde 1 or 2 with a phosphorane of the formula a5 fa «i/S/V results in the compounds of the general formula IV (wittig reaction).

Preparation of t&e phosphorus ylids used: 1. ‘Xsobutylcarbonylmethylenetriphenylphosphorane a. bromomethyl isobutyl ketone ml of bromine are added at 0*C to 50 ml of isobutyl methyl ketone in 240 ml of methanol and, after the addition, stirring is carried out at +10 C for 1.5 hours. 360 ml of water are then added and the reaction mixture is stirred at room temperature for a further 16 hours.

For working up, saturated sodium chloride solution is added to the reaction mixture, the organic phase which separates is removed and the aqueous phase is extracted with ether. The combined organic phases are washed with 10 % WagCOj solution and dried over NajSO^. After filtration, the solvent is drawn off under a water-jet vacuum and the residue is distilled. The main fraction contains 53.7 g of bromomethyl isobaryl ketone of b.p.^ 67-69‘C, b. isobutylcarbonylmethylenetriphenylphosphonium bromide Bromomethyl isobutyl ketone (53.6 g) and triphenylphosphine (78.5 g) are intimately mixed in a 500 ml round-bottomed flask and, when the initial strong heat generated has subsided, the reaction mixture is left for 12 hours at room temperature under nitrogen. The solid reaction mass is then taken up in 330 ml of methylene chloride and heated under reflux for 30 minutes. After the addition of 500 ml of ether, the mixture is allowed to cool to room temperature and the product is isolated by filtration. After drying, 111.7 g of the phosphonium salt of melting point 244-245‘C are obtained. c. Isobutylcarbonylmethylenetriphenylphosphorane 1500 ml of methylene chloride and 1500 ml of 2N h’aOH are added in succession to 111.6 g of the phosphonium bromide obtained in b. and the reaction mixture is stirred at room temperature for 30 minutes. The organic phase is separated, washed with water and dried over Na2S04. The solid residue obtained after concentration is recrystallised from tert.-butyl methyl ether and yields 72.2 g of the ylid of melting point 120-121’C. 2. Isoamylcarbonylraethylenetriphenylphosphorane The title compound is formed analogously to the process described in l. by bromination of isoamyl methyl ketone, 15 reaction of the bromide with triphenylphosphine to form the phosphonium salt and formation of the ylid with 2N NaOH.

From 50.0 ml of isoamyl methyl ketone and 18.2 ml of 23 bromine, there are obtained after working up by distilla· tion 54.68 g of l-bromo-5-methyl--hexan-2-one of h.p.15~20 80-3SC From 54.58 g of the bromide and 74.14 g of triphenylphosphine there are obtained 91.6 g of the phosphonium 25 salt of melting point 230-233*CFrom 91.6 g of the phosphonium salt there are obtained, after treatment with NaOH and recrystallisation of the crude product from methylene chloride/ester, 69.8 g of the title compound of melting point 64-67C. 3. Isopropoxymethylcarbonylmethylenetriphenylphosphorane 2.43 g of sodium are dissolved in 150 ml of isopropanol. After the addition of 20.0 g of chlororaethylcarbonylmethylenetriphenylphosphorane (R.F. Hudson et al., J.

Org. Chem. 28 2446,, 1963) dissolved in 200 ml of isopropanol, heating under reflux is carried out for 8 hours. When cool,, the reaction mixture is poured into sodium chloride solution and extracted with ethyl acetate. The oily residue obtained after concentration no is chromatographed on silica gel with ethyl acetate to yield 9.53 g of the title compound of melting point 134'C. 4. (2-Isopropoxyethyl)-carbonyImethylenetriphenylphosphorane a. i-Bromo-4~isopropoxy-butan-2-one 26.9 ml of bromine are added dropwise at O’C to a solution of 68.2 g of 4-isopropoxy-2"butanone (F.3. Hasan et al., J. Biolog. Chem- 256, 7781, 1981) in 315 ml of methanol and stirring is then carried out at +10C for 1.5 hours. 470 ml of water are then added to the reaction solution and stirring is carried out at room temperature for 16 hours. For working up, the reaction solution is poured into saturated sodium chloride solution and extracted with ether. Distilla25 tion of the crude product yields 78.07 g of the bromine derivative of b.p.1^ 20 95C. b. 4-Isopropoxy-2-oxo-butyl-triphenylphosphonium bromide From 78.0 g of the bromide obtained in a. and 97.85 g of triphenylphosphine there are obtained by the process described in l. 133.35 g of the phosphoniuro salt of melting point 183*C. c. (2-Isopropoxyethyl)-carbonylmethylenetriphenyl phosphorane The phosphoniura bromide (133.2 g) obtained in b. is treated as described in 1. with 2N NaOH in methylene chloride. Recrystallisation of the crude product from ethyl acetate yields 64.38 g of the title compound of melting point 97C.

. (X-Ethylpropoxymethyl) -carbonylmethylenetriphenylphosphorane A solution of 3.04 g of sodium in 100 ml of 3-pentanol is reacted with 25.0 g of chloromethylcarbonylmethylenetriphenylphosphorane analogously to the preparation of isopropoxymethylcarbonylmethylenetriphenyXphosphorane. The title compound is obtained in the form of a crystallised oil of melting point 66-70*C. 6. Cyclopropylmethoxymefchylcarbonylmethylenetriphenylphosphorane A solution of 5.58 g of sodium in 25.0 g of cyclopropylmethanol and 200 ml of toluene is reacted with 30,0 g of chloromethylcarbonylmethylenetriphenylphosphorane analogously to the preparation of isopropoxymethylcarbonylmethylenetriphenylphosphorane.

The title compound is obtained in the form of a solid of melting point 121*C. 7. (3-Butyny 1)-carbonylmethylenetriphenylphosphorane .0 g of methylcarbonylmethylemetriphenylphosphorane are dissolved in 628 ml of tetrahydrofuran and, at -78C 41.3 ml of butyllithium (1.6 molar solution in hexane) are added dropwise. 5.0 ml of propargyl bromide are then added dropwise. After being heated to room temperature, the reaction mixture is poured onto ice/sodiura chloride solution and the mixture is extracted with ethyl acetate. After drying of the organic phase with sodium sulphate, 23.4 g of solid are obtained. Purification by column chromatography (silica gel, ethyl acetate) yields 15.4 g of the title compound of melting point 135-136‘C. 8, (3~Butenyl) -carbonylmethylenetriphenylphosphorane By reaction of 15.0 g of methyIcarbonylmethylenetriphenylphosphorane in 471 ml of tetrahydrofuran with 31.0 ml of butyllithium and 4.28 ml of allyl bromide analogously to 7, the title compound is obtained in the form of a crystallised oil of melting point 92S3'C.

By varying the keto component used for the preparation of the Wittig reagent it is possible to produce in an analogous manner other phosphoranes which can be reacted with, the aldehyde X or 2 analogously to the method described below, to give other compounds of the general formula IV.

BX&MMUB 1 After the addition of 3.02 g of i soamv Icar bony Imethylenetriphenylphosphorane, a solution of 1.6 g of 1(S),3(R)bis- (tert. -butyldimethylsilyloxy) -20 (Π) -methyl-9,10-secopregna-5S,7E,10(19)-triene-21 -carbaldehyde in 50 ml of toluene is stirred at 80 C under argon for 16 hours. The solvent is then drawn off under reduced pressure and the residue is chromatographed on silica gel with hexane/ethyl acetate. The main fraction yields 1.15 g of [ 1(S), 3(R)"fois~(tert.-butyldimethylsilyloxy)-9,io-secochola-5E, 7E,10(19), 23 (E) -tetraen-24-yl J-4-methyl-pentan5 1-one in the form of a colourless oil. 1H-NMR (CDC13): 5 = 0.01 ppm (s, 12H, S1-CH3), 0.56 (s, 3H, H-18), 0.87 (s, 18H, Si-t.-butyl); 0.88 (d, J = 7 Hz, 6H, C-(CH3)2), 0.95 (d, J = 7 Hz, 3H, H-21); 4.25 (m, 1H, H-3); 4.55 (m, 1H, H-1); 4.94 and 5.00 (s, each 1H, H-19); 5.82 and 6.46 (d, J = 11 Hz, each 1H, H-6, H-7); 6.10 (d, J = 16 Hz, 1H, H-24); 6.80 (m, 1H, H-23).

B3»HK£ 2 572 mg of cerium(III) chloride heptahvdrate are dissolved in 10 ml of methanol, and the compound (1.10 g) prepared 5 in Example 1, dissolved in 5 ml of methanol, is added thereto. After the addition of 61 mg of sodium borohydride, the reaction mixture is stirred at 0C for 30 minutes. For working up, it is poured into water, extracted with dichloromethane, dried (Na2S04) and concentrated. The mixture of diasteraoisomeric alcohols so obtained is separated by chromatography on silica gel with hexane/ethvl acetate. There are obtained, in the order of elution, 290 mg of 1(S) , SiRJ-bis-itert.-butyldimethylsi lyloxy )-24-( l-hydroxy-4-methylpentyl) -9,1025 seco-5E,7E, 10(19),23(E)-cholatetraene (epimer A) and 120 mg of epimer B. The epimers have identical NMR spectra.

^H-NMR (CDCI3): δ = 0.01 ppm (s, 12K, Si-CH3), 0.49 (s, 3m, H-18), 0.86 (s, 18H, Si-t - -butyl); 0.86 (d, J - 7 Hz, 3© 6H, C-(CH3)2); 0.88 (d, J = 7 Hz, 3H, H-21); 4.16 (m, 1H, H-3); 4.48 (m, 1H, H-1); 4.88 and 4.93 (s, each 1H, H-19); 5.40 (dd, J = 15.5 and 7 Hz, 1H, H-24); 5.55 (m, 1H, H-23); 5.77 and 6.40 (d, J = 11 Hz, each 1H, H-6, H-7).

EXAMPO 3 After the addition of 44 mg of anthracene and 0.01 ml of triethylamine, a solution of 290 mg of the product obtained in Example 2 (epimer A) in 80 ml of toluene is irradiated in a Pyrex immersion reactor by means of a high-pressure mercury lamp (Philips HPK 125). The irradiation time is 3.5 minutes and thorough mixing of the solution is ensured by introducing a stream of nitrogen. Concentration and chromatography on silica gel with hexane/ethyl acetate yield 241 mg of 1(S),3(R)-bis(tert. -butyldimethylsilyloxy)-24- (1-hydroxy-4-methylpentyl )-9, lO-secochola-SZ^VE, 10(19) e23(E)-tetraene in the form of a colourless oil. [c]2° + 49.6* (CHC13, C=0.425).

Analogous treatment of 120 mg of the polar isomer obtained in accordance with Example 2 (epimer 3) yields 113 mg in the form of a colourless oil [g]20 + 41.4’ (CKC13, ¢=0.285).

EXAMPLE 4 = After the addition of 1.31 ml of a 1M solution of tetrabutyl ammonium fluoride in THF, a solution of 225 mg of the product obtained from epimer A according to Example 3 in 5 ml of THF is stirred at 60C for 60 minutes, when cool, the reaction mixture is poured into saturated sodium chloride solution and extracted with ethyl acetate. The crude product is chromatographed on silica gel with hexane/ethyl acetate and yields 85 mg of 24-( l-hydroxy-4-methylpentyl )-9, X0-secochola-5Z,7E,10(19), 23E-tetraene-l(S) ,3(R)-diol in the form of a white foam. 1H-NMR (CDC13): 6 = 0.57 ppm (s, 3H, H-18), 0.84 (d, J = 7 Hz, 3H, H-21); 0.92 (d, J = 7 Hz, 6H, C-(CH3)2); 4.03 (m, 1H, H-25); 4.23 (m, 1H, H-3); 4.43 (ra, 1H, H-l); .00 and 5.33 (s, each 1H, H-19); 5.45 (dd, J = 15.5 and Hz, IK, H-24); 5.60 (m, 1H, H-23); 6.02 and 6.38 (d, J = 1 Hz, each 11H, H-6, K-7)„ Analogous treatment of the product (95 mg) obtained from epimer 3 in accordance with Example 3 yields 35 mg of the W epimeric triol in the form of a colourless oil. The NMR spectra of the epimers are identical.

EXAMPLE 5 Analogously to the process described in Example I, 2.05 g of l(S),3(R)-bis-(tert.-butyldi»ethylsilyloxy)-20(R) ii 5 methyl-9, io-secopregna-5S ,72,10(19) -tr iene-21-carbaldehyde in 53 ml of toluene are reacted with 3.4 g of isobutylcarbonylmethylenetriphenylphosphorane. Purification by chromatography yields [I(S),3(R)-bis-(tert.butyIdimethylsilyloxy)-9,10-secochola-5E,73,10(19),2o 23(E)-tetraen-24-yI)-4-methyl~butan-l-one of melting point 79-81 C (from ethanol). (o]p° + 52.6’ (CHC13, c=0.500).

EXAMPLE 6 Reduction of 1.75 g of the product obtained in Example 5, under the conditions of Example 2, yields 1(S),3(R)bis (tert.-butyldimethylsilyloxy)-24-( 1(R,S)-hydroxy-3roethyIbutyl)-9,10-secochola-53,7E, 10(19),23(E)-tetraene in the form off an oily mixture of the epimers. By chromatography on silica gel with hexane/ethyl acetate there are obtained, in the order of elution, 780 mg of epimer A and 600 mg of epimer 3 in the form of colourless oils that are not distinguishable from each other in NMR spectroscopy.

EXAMPLE 7 By triplet-sensitised photoisomerisation analogously to Example 3 and subsequent silyl ether cleavage analogously to Example 4 there are obtained from 700 mg of the epimer A obtained in accordance with Example 6 240 mg of 24-(1 -hydroxy- 3 -me thy 1buty1)-9,X 0 -secocho 1 a- 5 2, 7 E , SO 10( 19), 23E-tetraene-l (S), 3 (R)-diol (compound A) having a „ 20 decomposition range of 119-125 C, + 38.3 (methanol, c=0.505).

Analogous treatment of 330 mg of epimer B yields 129 mg of 24-(l~hydroxy~3-methylbutyI )-9 „ 10-secochola15 52,.7E, 10(19),23E-tetraene~X(S),. 3(S)-diol (compound 3) having a decomposition range of 139-145C, [cj]20 + 54.8" (methanol, c=0.505).

EXAMPLE 8 After the addition of 200 mg of lithium tri-tert»2C* butoxyaluminium hydride, a solution of 170 mg of the product obtained in accordance with Example 5 in 5 ml of THF is stirred at room temperature for 90 minutes. For working up, 0.8 ml of saturated KH^Cl solution is added, the mixture is filtered, and the filtrate is concen25 traced. Chromatography of the crude product on AI2O3 (Merck, neutral, stage III) yields 108 mg of 1-[1(S),3 (R) -bis-(tert.-butyldimethyIsilyloxy) S, 10-secochola5Ξ,7E, 10( 19)-trien-24-yl]-3-methyl-butan-X-one in the form of a colourless oil.

XH-NMR (CDCI3): δ = 0.53 ppm (s, 3H, H-18)? 4.22 (η, 1H, H-3); 4.54 (ra, 1H, H-1); 4.93 and 4.98 (m, each IK, H-19); 5.82 and 0.46 (d, J = 11 Hz, each 1H, H-6, H-7).

EXAMPLE 9 Photochemical double-bond isomerisation analogously to Example 3 and silyl ether cleavage analogously to Example 4 yield from 100 mg of the product of Example 8 50 mg of 1-( 1 (S),3(R)-dihydroxy-9,lO-secochola-52,7E,10 (19) -trien-24-yI ]-3-methy1-butan-l-one.

UV (methanol): = 212 nm (£ = 14 300), 265 (15 860).

JO EXAMPLE 10 Reaction of 1.6 g of 1(S) ,3{R)~bis-(terfc.-butyldimethylsilyloxy )-20( R) -methyl-9,10-secopregna-5E,7E, 10 (19)triene~2i-carbaldehyde with (2-isopropoxyethyl)~carbonylseethylenetriphenylphosphorane analogously to Example 1 yields 1.15 g of l"(l(S),3(R)-bis~(tert.-butyldimethylsilyloxy)-9,10-secochola-5E, 7E, 10 ( 19), 23(E)-tetraer»-24yl ]-3-isopropoxy-propan~l-one in the form of a colourless oil. 1H-NHR (CDC13): 6 = 0.01 ppm (S, 12H, Si-CH3), 0.55 (s, 3H, H-18), 0.86 and 0.90 (s, each 9H, Si-t.-butyl),- 0.96 (d, J = 7 HZ, 3H, H-21); 1.15 (d, J = 7 Hz, 6H, C-(CK3)2)." 3-60 (m, 1H, CH-O); 3.73 (t, J = 7 Hz, 2H, CH2-O); 4.23 (ηι, 1H, H-3); 4.55 (m, 1H, H-1); 4.95 and 5.00 (m, each 1H, H-19); 5.83 and 6.46 (d, J = ll Hz, each 1H, H-6, H-7); 6.11 (d, J = 15.5 Hz, 1H, H-24); 6.87 (m, 1H, H-23).

EXAMPLE 11 By reduction analogously to Example 2, photoisomerisation analogously to Example 3 and silyl ether cleavage analogously to Example 4 there are obtained from 1.05 g of the product prepared according to Example 10 143 mg of 24-(1(R,S) -hydroxy-3 isopropoxypropyl) -9,10-secochola5Z,7Ef10(19),23-tetraene-l(S), 3(R)-diol in the form of a 1:1 mixture of the diastereoisomers, which can be separated by high-pressure liquid chromatography. The isomers have identical NMR spectra. iH-NMR (CDC13): 6 = 0.57 ppm (s,, 3H, K-18), 0.94 (d, J = 7 Hz, 3H, H-21)? 1.15 (d, J = 7 Kzt 6H, C(CH3)2), 4.17 (m, 1H, H-3)? 4.21 (m, 1H, H-25)j 4.38 (m, 1H, H-l); 4.98 and 5.29 (ra, each 1R, H-19)? 5.45 (dd, J = 15.5 and 7 HZ, 1H, H-24); 5-63 (m, 1H, H-23)? 6.02 and 6.38 (d, J = 11 Hz, each 1H, H-6, H-7).

EXAMPLE 12 Using aldehyde L and isopropoxymethylcarbonylmethylenetriphenylphosphorane as starting materials,, there is obtained analogously to the sequence of Examples 1-4 isomer 3 (5Z,7Ξ,22E,X(S),3(R),24(S)~9,10~seco-24a,24bdihomo-24b-oxacholesta-5,7,10( 19)22-tetraene-l,3,24» triol) of melting point 131-132'C, EXAMPLE 13 Using aldehyde i and (2-isopropoxyethyl )-carbonylmethylenetriphenylphosphorane as starting materials, there is obtained analogously to the sequence of Examples 1-4 isomer 3 (5S,7E,22E,1(S) ,3(R),24(3)-9,10-seco24a, 24b, 24c-trihomo-24c-oxacholesta-5,7, lO(19)22-tetraene-l,3,24-triol) of melting point 125-125'C.

EXMffiexjg ι< Analogously to Example 1, 0.85 g of 1(S), 3(R)-his-(tert.~ butyldimethylsilyloxy)-20 (R)-methyl-9, lOrsecopregna53,7E,10(X9)~triene~2i-carbaldehyde is reacted with 4.5 g of cyclopropylmethylcarbonyltriphenylphosphorane.

Purification by chromatography on silica gel with hexane/ethyl acetate yields 500 mg of l(S),3(R)-bis(tert.-butyldimethylsilyloxy )-26,27-cyclo-24a, 24b-dihomo9.10- secocholesta-5E,7E, 10(19)-23B-tetraen-24a-one in the HO form of a colourless foam.

^H-NMR (CDC13): & « 0.01 ppm (s, 12H, Si-CH3)? 0.09 and 0.50 (m, each 2H, H-26 and H-27); 0.50 (s, 3H, H-18); 0.83 and 0.85 (s,, each 9H, Si-t.-butyl); 0.91 (d, »5 J = 7.,3 Hz, 3H, H-21); 0.96 (m, 1H, H-25); 2.47 (d, J = 5 Hz, 2H, H-24b); 4.16 (m, 1H, H-3); 4.47 (m, IK, H-l); 4.89 and 4.93 (s, each IK, H-19); 5.77 and 6.40 (d, J = 11 Hz, each IB, H-6 and H-7); 6.08 (d, J = 15.5 Hz, K-24); 6.75 (ddd, J = 15.5, 9 and 6.5 Hz, 1H, H-23).

BXAKPUS 15 Reduction of the product obtained in Example 14, analogously to Example 2, yields 200 rag of 1(S),3(R)-bis(tert. -butyldimethylsi lyloxy)-26,27-cyclo-24a, 24b-dihomo9.10- secocholesta-5E, 7S, 10( 19 )«-23E-tetraen-24a(R,S)-ol in the form of oily mixture of the epimers, which are not distinguishable from each other in NMR spectroscopy.

(CDC13): 5 = 0.01 ppm (s, 12H, Si-CH3); 0.09 and 0.40 (ra, each 2H, H-26 and H-27): 0.50 (s, 3H, H-18); 0.68 (ra, 1H, H-25); 0.81 and 0.86 (s, each 9H, Si-t.30 butyl); 0.88 (d, J = 7 Hz, 3H, H-21); 1.40 (t, J = 7 Hz, H-24b); 4.13 (m, 1H, H-24a); 4.17 (m, IK, H~3); 4.49 (ra, 1H, H-l); 4.38 and 4.93 (s, each IB, B~19); 5.45 (dd, J = 15.5 and 6.5Hz, IH, H-24); 5.59 (ddd, J = 15.5, 7 and 6.5 Hz, IH, H-23); 5.77 and 6.40 (d, J = 11 Hz, each IH, H-6 and H-7).

EXAMPLE 16 Analogously to Example 3, by triplet-sensitised photoisomerisation and removal of the protecting groups analogously to Example 4 there are obtained from 190 mg of the compound described in Example 15 86 mg of 26,27cyclo-24a, 24b-dihomo-9 , lO-secocholesta-52,7.8,10( 19), 23E10 tetraene-l(S) ,3(R) ,24a(R,S)~triol in the form of a 1:1 mixture of the diastereoisoraers, which can be separated by high-pressure liquid chromatography. The NMR spectra of the two diastereoisomers are identical.

•^-H-NMR (CDC13): ί = 0.09 and 0.49 (ra, each 2H, H-26 and ii5 H-27)» 0.53 (st, 3H, H-18); 0.70 (», IH, H-25); 0.93 (d, J = 7 Hz, 3Η» H-21); 4.18 (®, IH, H-24a); 4.22 (ffl, IH, K-3); 4.43 (m, IH, H-l); 5.00 and 5.32 (s, each IH, H-19); 5.50 (dd, J = 15.5 and 6.5 Hz, H-24); 5.64 (ddd, J = 15.5, 7 and 6.5 Hz, IH, H-23); 6.02 and 6.38 (d, J = 11 Hz, each IH, H-6 and H-7).

EXAMPLE 1? Using aldehyde 1 and (1-ethylpropoxymethyl)-carbonylmethylenetriphenylphosphorane as starting materials there is obtained analogously to the sequence of Examples 1-4 isomer B (5Z,7E,22E,1(S) ,3(R) ,24(5)-26,27-dimefchyl24a, 24b-dihorao-24.b-oxa-9, l0~secocholesta-5,7,10(19)22tetraene-l,3,24-triol) of melting point 103-105’C.

BXAMKUS IS Using aldehyde 1 and cyclopropvlmethoxymethylcarbonyl31 roethylenetriphenylphosphorane as starting materials there is obtained analogously to the sequence of Examples 1-4 isomer 3 (5Z,7E,22E,1(S),3(R),24(S)-26,27-cyclo-24a,24b, 24c-trihorao-24b-oxa-9,10~secocholesta-5,7,10(19)225 tetraene-1,3,24-triol). iH-NMR (DMSO-d6): 6=0.16 ppm (m, 2H); 0.43 (m, 2H); 0.53 (S, 3H)y 1.00 (d, J = 5 Hz, 3H); 3,21 (m, 4H); 4.00 (m, 2H)y 4.19 (m, 1H); 4.51 (d, J = 5 Hz, 1H); 4.70 (d, J = Hz, 1H); 4.75 (m, ΪΗ) ? 4,82 (d, J = 5 Hz, 1H) 5.21 (m, W 1H; 5.39 (m, 2H); 5.98 (d, J = 11 Hz, 1H)? 6.18 (d, J = XI Hz, 1H).

EXAMPLE 19 Using aldehyde 1 and (3-butynyl)-carbonylmethylenetriphenylphosphorane as starting materials there is obtained S5 analogously to the sequence of Examples 1-4 isomer 3 (5Z,7E,22E-1 (S) ,3(R) ,24(S)-24-(3-butynyl)-9,l0-secochola5,7,lO(19)22-tetraeR®-l,3,24-triol) of melting point 115-118’C.

EXAMPLE 20 20 Using aldehyde 1 and (3-butenyl )~carbonylmethylenetriphenylphosphorane as starting materials there is obtained analogously to the sequence of Examples 1-4 isomer B (52,7Ξ,22E-1 (S),3(R),24(S)-24-(3-butenyl)-9,10-secochola5,7,10(19)22-tetraene-l,3,24—triol) of melting point 146~147*C.

Claims (1)

1. CLAIMS: P'ATKsjT COJMS 1. Side-chain homologues of vitamin D derivatives of the formula I wherein 5 Rl is a hydrogen atom, a hydroxy group or an acyloxy group having from 1 to 9 carbon atoms, R 2 is a hydrogen atom or an acyl group having from 1 to 9 carbon atoms, R 3 or R 4 is a hydroxy group or an acyloxy group having 10 from 1 to 9 carbon atoms and the respective other substituent is a hydrogen atom, or R 3 and R^ together represent an oxygen atom, R 5 and R s each independently of the other is a linear or branched alkyl radical having up to 5 carbon atoms, a !5 trifluoromethyl group or, together, represent a saturated, unsaturated or aromatic carbocyclic or, with the inclusion of 1 or 2 N-, O- or S-atoms, heterocyclic 3-, 4-, 5- or 6-membered ring formed with the tertiary carbon atom, 20 B and D either each represents a hydrogen atom or together represent a second bond (E-configured double bond) and either A is a direct bond between carbon atoms 20 and 22 and X is an alkyleneoxy radial -(CH 2 ) n O- wherein n = 1 to 3 or A is a methylene bridge (-CH 2 “) between carbon atoms 20 and 22 and 5 X is an alkylene radical -(CH 2 ) n “ or an alkyleneoxy radical ~(CH 2 ) n O- wherein n = 1 to 3 or, when A is a direct bond and 3 and D together represent a second bond, -X< represents one of the radicals -CH 2 -O~CH 2 -<^] , -(CH 2 ) 2 -= or ~(CH 2 ) 2 -=. w 2. Vitamin D derivatives according to claim 1, wherein Rl represents a hydroxy group. 3. Vitamin D derivatives according to claim represents a hydrogen atom. 1, wherein R 2 115 4. vitamin D derivatives according to claim or R 4 represents a hydroxy group. 1, wherein R 3 5. Vitamin D derivatives according to claim in X is 1 or 2. 1, wherein n 6. Vitamin D derivatives according to claim and R s represent methyl groups. 1, wherein R 3 20 7. Vitamin D derivatives according to claim 1, wherein R 5 , R s and the tertiary carbon atom form together a cyclopropyl ring. 8. 24-(I (R)-hydroxy-4-mefchylpentyX)9,10-secochola52 g 73,10(19),23E-tetraene-l(S),3(R)-diol, 24—(1(S)-hydroxy-4-methylpentyl)-9,10-secochola-5Z,7E, 10(19),233-tetraene-l(S),3(R)-diol, 24~ (1 (R) -hydroxy-3-methylbutyl) -9, 10-secochola-SZ,7E, 10(19),23E-tetraene-l(S),3(R)-diol, 24~ (1 (S)-hydroxy-3-methylbutyl)-9,10-secochola-5Z, 7E, 10 (19),233-tetraene-l(S),3(R)-diol, 5 24-( 1(R) “hydroxy-3~methylbutyl )-9, I0~secochola-5Z,7E,10(19)-triene~l(S),3(R)-diol, 24-(1 (S)-hydroxy-3-methylbutyl)-9,10-secochola~52,7E,10(19)~fcriene-l(S),3(R)-diol, 24- (1 (R) -hydroxy-3-isopropoxyptopyl) -9,10-secochola?G 5Z,73,10(19),23E-tetraene-l(S) ,3'R)~diol, 24- (1(S)-hydroxy-3-isopropoxypropyl)-9,10-secochola5Z ,73,10(19), 23E-tetraene-l(S), 3(R)-diol, 2. 4 - isopropoxymethyl- 9 e 10-secocho la- 5 Z , 73,10(19), 223tetraene-l(S), 3. (R),24(R)-triol, 15 24-lsopropoxymethyl“9,10-secochola-5Z, f 73,10(19) ,223tetraene-i(S), 3(R),24(S)-triol, 24- (2-isopropoxyethyl) -9,10-secochola-5Z ,73,10(19), 22Etetraene-l(S), 3(R),24(R)-triol, 24-( 2-isopropoxyethyl)-9,10-secochola-SZ,72,10(19),22Ξ2G tetraene-1(S), 3 (R), 24 (S)-triol, 26,27-cyclo-24a,24b-dihomo-9,10-secocholesta52,73, 10(19),23E-tetraene-l(S),3(R),24a(R)-triol, 26,27~cyclO“24a,24b-dihomo-9,10-secocholesta-5Z,7E,10(19),23E~tetraene~l(S),3(R),24a(S)-triol. 25 9. Process for the manufacture of side-chain homologues of vitamin D derivatives of the formula I wherein R 1 , R 2 , R 3 , R 4 , R 5 and R® and A, B, D and X have the meanings given in claim 1, characterised in that a compound of the general formula IV wherein R x ‘ is a hydrogen atom or a protected hydroxy group and R 2 ' is a hydroxy-protecting group and A, X and R 5 and R s have the meanings given in formula I, 50 if desired after selective hydrogenation of the double bond in the side chain to form a compound of the general formula IVa (IVa), wherein R 1 *, R 2 „ A, X and R 5 and R® have the meanings given in formula IV, and if desired after reduction of the carbonyl function and, optionally, after separation of th© mixture of epimeric hydroxy compounds of the general formulae Ilia and Illb formed by the reduction (ΪΠ2Ι *«-0H = C 4. -0M (ΙΠ&) aawOH s Θ-ΟΗ ί© wherein R 1 ^, R 2 * t , A, X and R 5 and R 6 have the meanings given in formula IV and 3 and D have the meanings given in formula I, is converted by irradiation with ultraviolet light, with the stereoisomerism at the 5,6-double bond being reversed, into a compound of the general formula II wherein R 1 , R 2 ' , A, B, D, X and R 5 and R 3 have the meanings 5. Given in formula Illa/IIlb, which is then converted by removal of any hydroxyprotecting groups and, optionally, by partial or complete esterification of the hydroxy groups, into a compound of the general formula I. 6. 10 10» Pharmaceutical preparations, characterised in that they contain at least one compound according to claims 1 to 8 and a pharmaceutically acceptable carrier. 7. 11. Use of compounds according to claims 1 to 8 for the manufacture of medicaments. 12. A compound substantially as hereinbefore reference to the Examples. described with 13. A composition substantially as hereinbefore desc with reference to the Examples. ribed 14. A process substantially as hereinbefore reference to the Examples. described with 15. A use substantially as hereinbefore reference to the Examples. described with Dated this 5th day of February 1991