IE852443L

IE852443L - Vitamin d derivatives

Info

Publication number: IE852443L
Application number: IE852443A
Authority: IE
Original assignee: Wisconsin Alumni Res Found
Priority date: 1984-10-04
Filing date: 1985-10-04
Publication date: 1986-04-04
Also published as: AU2761488A; GB2188932A; IT1190401B; GB2167070A; NL8520265A; GB2188932B; JPH05222089A; DK158990B; DK15290A; DK158989B; JPH0689022B2; BE903376A; JPH0635475B2; IE58104B1; DK158991B; AU605007B2; DK111188A; FR2571369A1; GB8524479D0; DK111188D0

Abstract

New 24-homo-vitamin D compounds, methods for preparing the same and novel intermediate compounds. The compounds are characterized by vitamin D-like activity of the order of 1$g(a),25-dihydroxyvitamin D3?, the recognized circulating hormonal form of vitamin D, or various of its derivatives and are useful in the treatment of disease state characterized by calcium-phosphorous imbalances. [WO8602078A1]

Description

U >< 'I J I /I. kJ ^ i 1 u This invention relates to novel 24-homovitamin D derivatives.

Vitamin D is known to regulate calcium and phosphorus metabolism in animals and humans and it has now been firmly established that the biological efficacy of vitamin D depends upon its metabolic 5 conversion, in vivo, to hydroxylated derivatives. Thus vitamin is hydroxylated in vivo to 25-nydroxyvitamin in the liver which in turn is converted into 1*,25-dihydroxyvitamin in tne kidneys. It is tne latter ccopound which is now recognized as being the circulating hormonal form of vitamin D.

Because of their biological activity in promoting calcium and phosphorus transport in tne intestine and the mobilization and mineralization of bone these forms of vitamin D are important pharmaceutical products which are eminently suitable for use in the treatment of various bone disorders.

New Derivatives of vitamin have now been found which express excellent vitamin D-like activity and which, therefore, could readily serve as a substitute for vitamin in known applications, such as tne treatment of various disease states manifesting calcium and phospnorus imbalance such as hypoparathyroidism, osteodystrophy, osteomalacia and 20 osteoporosis.

These derivatives are 24-nomovitamins, particularly W,^5-aihydroxy-22E(orZ)-denydro-24-homovitamin D~ and 1^,25-dinydroxy-24-homovitamin D^. 3 The compounds of the present invention can be represented by the formula: where and R^ are each independently hydrogen, acyl having frcm 1 to 4 carbon atcms or benzoyl and and R^ each represent hydrogen atoms or taken together form a carbon to carbon bond.

The ccnpounds of this invention can be prepared in accordance with the following schematic and detailed description where like numbers identify like ccrnpounds.

In accordance with the process of this invention: Bisnorcholenic acid acetate (a) was reduced with lithium aluminum hydride and subsequently oxidized with dichloro-dicyanobenzoguinone to afford the 1,4,6-triene-3-one (b) in 5 47% yield. The 22-THP-ether of b was treated with alkaline hydrogen peroxide to give the la, 2a-epoxide (1) in 41% yield. Reduction of (1) with lithium and airmonium chloride in liquid amio tia-tetrahydrofuran at -78°, and subsequent treatment with chlorcmethyl methyl ether provided the dirnethyaxynethyl ether 10 (MCMO) (2^) in 38% yield. Removal of the THP group, followed by Swern oxidation gave the aldehyde (4) in 81% yield. This was reacted with vinylmagnesium brcmide to provide the allyl-aloohol (_5) in 94% yield. This alcohol was heated in refluxed xylene with triethyl orthoacetate and a catalytic amount of 15 propionic acid, to afford the ester (6) in 93% yield. Then, the ester (f>) v;as reacted with me thy Ima gnesium bromide to provide the alcohol {1) in 93% yield. Removal of MOM group, followed by acylation, e.g. acetylation gave (22E)-1 ,3B-diacetoxy-25-hydroxy-24-hcno-cholesta-5,22-diene (9) in 73% yield.

Ally lie brcmination of (9) with N-brcmosuccinimide, followed by treatment with tetra-n-butylaimonium bromide and then with tetra-n-butylaimDnium fluoride gave the 5,7,22-txiene (10) as a main product in 24% yield. The 5,7-diene (10) was irradiated with a medium pressure mercury lamp in 25 benzene-ethanol for 5 min, subsequently refluxed for 1 hr, and then hydrolyzed to afford (22E)-la,25-dihydroxy-22-dehydro-24-hotnovitamin (11) in 22% yield by analogous methods well known in the art other acylates or benzoates can be prepared which would be equally useful in the succeeding process steps. 30 The 5,22-diene (9) was selectively hydrogenated, e.g. using tetra n-butylainnonium fluoride, to provide the 5-ene (12) in 92% yield. This canpound was converted to la,25-dihydraxy-24-homovitamin D3 d4) via the 5,7-diene (13) as described above in 12% overall yield.

In the following detailed description melting points were determined with a hot-stage microscope and were uncorrected. "*"H-NMR spectra were taken 6 with a Hitachi* R-24A (6G MHz) in CDCl^ with Me^Si as an internal standard, unless otherwise noted. Mass spectra were obtained with a Shimadzu QP-1000 mass spectrcmeter at 70 eV. UV spectra were obtained in ethanol solution with a Shimadzu 5 UV-200 double beam spectrophotometer. Column Chromatography was effected using silica gel (E. Merck*, Kieselgel 60, 70-230 mesh). Preparative thin layer chromatography was carried out on precoated plates of silica gel (E. Merck, Kieselgel 60 M M ., 0.25 nm thickness). The usual work-up refers to 254 dilution with water, extraction with an organic solvent indicated in parenthesis, washing the extract to neutrality, drying over anhydrous magnesium sulphate, filtration, and removal of the solvent under reduced pressure. The following abbreviations are used; THP - tetrahydropyrany1; THF -15 tetrahydrofuran; ether - diethyl ether, MeOH - methanol, MOM -methoxymethyl. Temperatures are in ° centigrade. 2 2-Rydroxy-23,24-dinorchola-l,4,6-triene-3-one (b) lb a solution of 30-acetoxydinorcholenic acid (a) (7.0 g, 18.04 itmole) in THF (20 mL) lithium aluminum hydride (3.0 g, 20 78.95 mmole) was added. This mixture was stirred at 60°C for 14 h. To this reaction mixture water and ethyl acetate were carefully added. Filtration and removal of the solvent gave the residue (5.2 g). This in dioxane (140 mL) was treated with dichlorodicyanobenzoquinone (11.7 g, 51.54 itirole) under 25 reflux for 14 h. After cooling to rocxn temperature the reaction mixture was filtered and the filtrate was evaporated to leave the residue, which was applied to a column of alumina (200 g). Elution with dichloromethane provided the trienone (b) (2.8 g, 47%) mp 156-157° (ether) UVXEt0H nm (e): 299 — 1 ITBX (13000), 252 (9200), 224 (12000), TI-NMR (CDC13)6: 0.80 (3H, s, 18-H3), 1.04 (3H, d, J=6 Hz, 21-iy , 1.21 (3H, s, 19-H3), 3.10-3.80 (3H, n, 22-H2 and CJH), 5.90-6.40 (4H, m, 2-H, 4-H,6-H, and 7-H), 7.05 (1H, d, J=10 Hz, 1-H), MS m/z: 326 (M+), 311, 308, 293, 267, 112. 35 la, 2a-Bpoxy-22-tetrahydropyranyloxy-23,24-dinorchola-4,6-dien- * Registered Trade Mark 7 3-one (1) The alcohol (b) (2.7 g, 8.28 nroole) in dichlorome thane (50 mL) was treated with dihydropyrane (1.5 mL, 16.42 imole) and p-toluenesulfonic acid (50 mg) at rocm temperature for 1 5 h. The usual work-up (ethyl acetate for extraction) gave a crude product. To a solution of this product in MeOH (70 mL), 30% ^2^2 10% NaOH/MsOH (0.74 mL) were added and this mixture was stirred at rocm temperature for 14 h. The usual work-up (ethyl acetate for extraction) gave a crude 10 product, which was applied to a column of silica gel (50 g). Elution with benzene-ethyl acetate (100 : 1) provided the epoxide (1) (1.45 g, 41%): mp 113-115° (hexane) UVX^^nm (e): i IIBX 290 (22000), TI-NMR (CDCl^S: 0.80 (3H, s, 18-H.j), 1.07 (3H, d, J=6 Hz, 21-H3), 1.18 (3H, s, 19-H3), 3.38 (1H, dd, J=4 and 15 1.5 Hz, 1-H), 3.55 (1H, d, J=4 Hz, 2-H), 3.30-4.10 (4H, m, 22-H2 and THP), 4.50 (1H, m, THP), 5.58 (1H, d, J=1.5 Hz, 4-H) , 6.02 (2H, s, 6-H and 7-H) , MS m/z: 342 (M+ - HP) , 324 (M+ - THPOH), 309, 283, 85. la, 3 ft-Diirethoxymethoxy-23,24-dinorchol-5-en- 2 2-tetra-20 hydropyranyl ether (2) Lithium (5.00 g) was added in small portion to liquid arrrronia (200 ml) at -78° under argon atmosphere during 30 min. After stirring for 1 hr at -78°, la,2a-epoxy-22-tetrapyranyl-oxy-23,24-dinorchola-4,6-diene-3-one (1) (2.00 g, 4.69 m mol) 25 in dry THF (150 ml) was added dropwise at -78° during 30 min, and this mixture was stirred for 1 hr at -78°. To this reaction mixture, anhydrous NH^Cl (60 g) was added in small portion at -78° during 1 hr. After 1.5 hr the cooling bath was removed and most of the arrmonia was removed by' bubbling 25 argon. The usual work-up (ether was used as a solvent) gave a crude product. This was treated with chloro-methyl methyl ether (2.0 ml, 26.34 m mol) and N,N-diethylcyclohexylamine (4.6 ml, 24.93 m mol) in dioxane (20 ml) at 45° for 24 hr. The usual work-up (ethyl acetate) gave a crude product, which 30 was applied to a 'column of silica gel (40 g). Elution with 8 hexane-ethyl acetate (5 : 1) provided the dimethoxymethy 1 ether (2) (922 mg, 38%) as an oil. ^H-NMR 6 0.70 (3H, s, 18-H3), 1.02 (3H, s, 19-H3), 1.04 (3H, d, J=6 Hz, 21-H3), 3.34 (3H, s, -o-oy, 3.37(3H, s, -0-CH3),4.63 (2H, ABq, J=7 Hz, 5 AAB=11 Hz, la-0-CH2-0-), 4.64 (2H, s, 30-O-CH2-O-), and 5.50 (1H, m, 6-H). la, 3ft-Dimethoxyroethoxy-23,24-dinorchol-5-en-22-ol P) The THP ether (2) (922 mg, 1.77 mmol) in 1HF (8 ml) and MeOH (8 ml) vras treated with 2M HCl (1 ml) at rocm temperature 10 for 2 h. The usual work-up (ethyl acetate) gave a crude product, which was applied to a column of silica gel (40 g). Elution with hexane-ethyl acetate (2 : 1) gave the alcohol (3) (678 mg, 88%) as an amorphous solid. ^H-NMR 6 0.70 (3H, s, 18-H3), 1.02(3H,s,19-H3), 1.04 (3H, d, J=6 Hz, 21-^), 3.34 15 (3H, s, -O-ay, 3.38 (3H, s, -0-CH3), 4.65 (2H, ABq, J=7 Hz, AAB = 11 Hz, la-0-CH2-0-), 4.66 (2H,s,3p-0-CH2-0-), 5.53 (lH,m,6-H). la, 3fl-Diirethoxymethoxy-23,24-dinorchol-5-en- 2 2-a 1 (4) To a solution of oxalyl chloride (0.27 ml, 3.09 mmol) in 20 dichloranethane (8 ml) dimethyl sulphoxide (0.44 ml, 6.21 irmol) was added at -78°C under argon. The mixture was stirred at -78°C for 10 min. To the solution the alcohol (3) (660 mg, 1.51 irmol) in dichlorcmethane (5 ml) was added at -78°C.

After stirring for 15 min, triethylamine (1.89 ml, 13.6 mmol) 25 was added. The mixture was stirred at -78°C under argon for 5 min, and warmed up to rocm temperature. The usual work-up (ether) gave a crude product, which was applied to a column of silica gel (30 g). Elution with hexane-ethyl acetate (4 : 1) gave the aldehyde (4) (607 mg, 92%) as a crystal, mp 71-72°C 30 (hexane) , "Si-NMR 6 0.74 (3H, s, 18-H3) , 1.04 (3H, s, 19-H3), 1.12 (3H, d, J=6 Hz, 21-H3), 3.35 (3H, s, -O-CH-j), 3.39 (3H, s, -0-CH3), 3.7 (1H, m, lp-H) , 4.65 (2H, ABq, J=7 Hz, AAB = 11 Hz, la-0-CH2-0-), 4.66 (2H, s, 3£-0-CH-0-), 5.52 (1H, m, 6-H), and 9.61 (1H, d, J=3 Hz, -CHO), Anal. Calcd for C26H4205: C, 35 71:85; H, 9.74. Found: C, 71.71; H, 9.68. 9 la, 3p-Dimethoxyrnethoxychola-5,23-dien-22-ol (5) To magnesium (70 mg, 2.92 mmol) in THF (3 ml) 50% solution of vinyl bromide in THF (0.42 ml, 2.98 irnol) was added. The mixture was stirred at room temperature under 5 argon for 30 min. To the resulting Grignard reagent the aldehyde (4) (595 mg, 1.37 mmol) in THF (6 ml) was added at room temperature. The mixture was stirred at roam temperature for 1 h. The visual work-up (ether) gave a crude product, which was applied to a column of silica gel (30 g). Elution 10 with hexane-ethyl acetate (3 : 1) gave the ally lie alcohol (5) (595 mg, 94%) as an amorphous solid. "4l-NMR 6: 0.70 (3H, s, 18-H3), 1.02 (3H, s, 19-H3), 3.35 (3H, s, -O-Cjy, 3.38 (3H, s, -O-ay, 3.69 (1H, m, 10-H), 4.20 (1H, m, 22-H), 4.64 (2H, ABq, J=7 Hz, AAB = 11 Hz, la-O-O^-O-), 4.65 (2H, s, 15 3p-0-CH2-0-), 5.52 (1H, m, 6-H), 4.90-6.0 (3H, m, 23-H and 24-H2). (22E) -la, 3ft-Djrrethoxymethoxy-27-norcholesta-5,22-dien-26-oic acid ethyl ester (6) A solution of the allylie alcohol (5) (590 mg, 1.28 20 rrnol), triethyl orthoacetate (1.0 ml, 5.46 mmol), propionic acid (4 drops), and xylene (8 ml) was refluxed under argon for 2 h. Removal of the solvent under reduced pressure gave the residue, which was applied to a column of silica gel (30 g). Elution with hexane-ethyl acetate (4 : 1) gave the ester (6) 25 (630 mg, 93%) as an oil. "^-NMR 6: 0.68 (3H, s, 18-H3), 0.97 (3H, d, J=6 Hz, 21-H3), 1.03 (3H, s, 19-H3), 1.24 (3H, t, J=7 Hz, -co2ai2qy, 3.35 (3H, s, -oay, 3.39 (3h, s, -o-ay, 3.70 (1H, m, 10-H), 4-H (2H, q, J=7 Hz, -C02CH2ay , 4.64 (2H, ABq, J=7 Hz, AAB = 11 Hz, la~0-CH2-0-) , 4.65 (2H, s, 30 3£-o-ch2-0-) , 5.29 (2H, m, 22-H and 23-H), 5.52 (IE, m, 6-H). If desired the 22E stereo isomer, compound (6), can be readily conveirted to the 22Z stereo iscxner by treatment with iodine. Thus, treatment of compound (6) in ether with a catalytic amount of iodine (2%) of the amount of (6) while 35 under diffuse daylight for 1 hr. results in a trans to cis isorerization which, after KPLC purification, (Zorbax-Sil column, 4.6 x 25 cm, 6% 2-propanol/hexane) yielded the 22Z stereo isomer. (22E) -la, 3ff-Diinethoxyirethoxy-24-homo-cholesta-5,22-diene-25-ol <Z> To a solution of the ester (6) (605 mg, 1.14 mmol) in THF (6 ml) 1M solution of methylmagnesium bromide in THF (4.5 ml, 4.5 irmol) was added at rocm temperature. The mixture was stirred at rocm temperature for 1 h. The usual work-up 10 (ether) gave a crude product, which was applied to a column of silica gel (30 g). Elution with hexane-ethyl acetate (3:1) gave the alcohol (7) (548 mg, 93%) as an oil. ^H-NMR 6: 0.68 (3H, s, 18-H3), 0.97 (3H, d, J=6 Hz, 21-H3), 1.01 (3H, s, 19-H3), 1.21 (6H, s, 26-H3 and 27-^), 3.33 (3H, s, -O-ay, 15 3.38 (3H, s, -0-CH3), 3.70 (1H, m, ip-H), 4.64 (2H, ABq, J=7 Hz, AAB = 11 Hz, la-0-CH2-0), 4.65 (2H, s, 3p-(>CH2-0-), 5.29 (2H, m, 22-H and 23-H), and 5.50 (1H, m, 6-H). (22E) -24-Homocholesta-5,22-diene-la,3S,25-triol (8) A solution of the dimethoxymethyl ether (7) (540 mg, 1.04 20 mrol) in THF (15 ml) vras treated with 6M HCl (3 ml) at 50°C for 2.5 h. The usual work-up (ethyl acetate) gave a crude product, which was applied to a column of silica gel (20 g). Elution with hexane-ethyl acetate (1 : 1) gave the triol (8) (428 mg, 95%) as a crystal, np 164-166°C (hexane-ethyl 25 acetate), ^-NMR 6: 0.68 (3H, s, 18-H3) , 0.95 (3H, s, J=6 Hz, 21-H3), 1.00 (3H, s, 19-H3) , 1.20 (6H, s, 26-H3 and 21-Yi^), 3.80 (1H, m, lp-H), 3.92 (1H, m, 3a-H), 5.30 (2H, m, 22-H and 23-H), and 5.53 (1H, m, 6-H). (22E) -la, 3 ft-Diace toxy-2 5-hydr oxy-2 4 -homocho I e s ta-5,22-diene 30 (9) A solution of the triol (8) (395 mg, 0.919 nmol) in pyridine (2 ml) vras treated with acetic anhydride (1 ml) at roan temperature for 16 h. The usual work-up (ethyl acetate) gave a crude product, which was applied to a column of silica 35 gel (20 g). Elution with hexane-ethyl acetate (2 : 1) gave i 1 the diacetate (9) (361 mg, 77%) as an oil. ^H-NMR 6: 0.67 (3H, s, 18-H3), 0.97 (3H, d, J=6 Hz, 21-H3), 1.07 (3H, s, 19-H3), 1.21 (6H, s, 26-H3 and 27-H3), 2.01 (3H, s, acetyl), 2.04 (3H, s, acetyl), 4.98 (1H, m, 3a-H), 5.05 (1H, m, 10-H), 5 5.31 (2H, m, 22-H and 23-H), and 5.52 (1H, m, 6-H). (22E) -la, 3ft-Diacetoxy-25-hydroxy-24-hariochalesta-5,7,22-triene (10) A solution of the 5-ene (9) (51 mg, 0.0992 mmol) and N-bromo-succinimide (21 mg, 0.118 mriol) in carbontetrachloride 10 (3 ml) was refluxed under argon for 20 min. After the mixture had been cooled to 0°C, the resulting precipitate was filtered off. The filtrate was concentrated below 40°C to leave the residue. This in 1KF (5 ml) vras treated with a catalytic amount of tetra-n-butylammonium bromide at rocm temperature 15 for 50 min. Then, the mixture was treated with a solution of tetra-n-butylaimonium fluoride in THF (3.5 ml, 3.5 mmol) at rocm tenperature for 30 min. The usual work-up (ethyl acetate) gave a crude product, which was submitted to preparative thin layer chromatography (hexane-ethyl acetate, 4 20 : 1, developed five times). The band of Rf value 0.48 was scraped off and eluted with ethyl acetate. Removal of the solvent provided the 5,7-diene (10) 12.5 mg, 24%), UVA^^ 293, 282, and 271. la, 25-Dihydroxy-22E-dehydro-2 4-horrovitamin (11) 25 A solution of the 5,7-diene (10) (7.3 mg, 0.0143 irmol) in benzene (90 ml) and ethanol (40 ml) was irradiated with with a medium pressure mercury lamp through a Vycol filter at 0°C under argon for 5 min. The reaction mixture was refluxed under argon for 1 h. Removal of the solvent tinder reduced 30 pressure gave a crude product, which was submitted to preparative thin layer chromatography (hexane-ethyl acetate, 4 : 1, developed five times). The band of Rf value 0.38 was scraped off and eluted with ethyl acetate. Removal of the solvent gave the vitamin D3 diacetate (1.8 irg, 25%). The band 12 of Rf value 0.43 was scraped off and eluted with ethyl acetate. Removal of the solvent recovered the 5,7-diene (10) (2.1 mg, 29%).

The vitamin diacetate (1.8 mg, 2.15 yrrol) in THF (4 ml) was treated with 5% KOH/MeOH (1 ml) at rocm temperature for 20 min. The visual work-up (ethyl acetate) gave a crude product, which was submitted to preparative thin layer chromatography (hexane-ethyl acetate, 1:2, developed three tines). The band of Rf value 0.43 was scraped off and eluted with ethyl acetate. Removal of the solvent gave the vitamin analogue (11) (1.4 mg, 90%). The purity of the product (11) was determined as 100% by high performance liquid chromatography (a Shimadzu LC-3A; column, Zorbax ZIL normal phase, 4.6 nm i.d. x 15 cm; solvent, MeQH-CH2Cl2, 1 : 49; flew rate, 3 ml/min; retention time, 11.5 min). The vitamin D_ EtOH analogue (11) had the following spectral data; : 265 nm, : 228 nm, MSm/z: 428 (I-l+), 410, 392 (base peak), mm n 374, 287, 269, 251, 152, 134, 123, 59, n-NMR (360 MHz) 6: 0.55 (3H, s, 18-H3), 1.02 (3H, d, J=6.6 Hz, 21-H3), 1.22 (6H, 20 s, 26-H3 and 27-H3), 2.32 (1H, dd, J=13.2 and 6.7 Hz), 2.60 (1H, dd, J=13.0 and 3.0 Hz), 2.83 (1H, dd, J=12.0 and 3.0 Hz), 4.23 (1H, m, W1/2) = 18.4 Hz, 3a-H), 4.43 (1H, m, Vl±/2 = 16.9 Hz, lp-H), 5.00 (1H, bs, W1/2 = 3.2 Hz, 19-H), 5.30 (1H, dd, J=15.0 and 7.1 Hz, 22-H or 23-H), 5.33 (1H, bs, W= 3.2 Hz, 25 19-H), 5.37 (1H, dd, J=15.0 and 5.8 Hz, 22-H or 23-H), 6.01 (1H, d, J=11.0 Hz, 7-H), 6.32 (1H, d, J=11.0 Hz, 6-H). la, 3ft-Diacetoxy-24-horoocholest-5-en-25-ol (12) A mixture of the 5,22-diene (9) (40 mg, 0.0778 rrmol) and 10% Pd-C (4 mg) in ethyl acetate (2 ml) was stirred at room 30 temperature under hydrogen for 3 h. The Pd catalyst was filtered off and the filtrate was concentrated to leave the residue, which was applied to a column of silica gel (5 g). Elution with hexane-ethyl acetate (4 : 1) gave the 5-ene (12) (37 mg, 92%) as an oil. "^I-NMR 6: 0.66 (3H, s, 18-H3) , 1.08 35 (3H, s, 19-H3), 1.20 (6H, s, 26-H3 and 27-H3), 2.02 (3H, s, 13 acetyl), 2.05 (3H, s, acetyl), 4.97 (1H,- m, 3<x-H) , 5.07 (1H, m, 13-H), 5.53 (1H, m, 6-H). la,3g-Diacetoxy-24-homocholesta-5,7-dien-25-ol (13) The 5-ene ('12) (19mg, 0.037 mmol) was converted, as described for (10), to the 5,7-diene (13) (5.8 mg, 31%).

UVXEt0H : 293, 282, 271 nm. max la,25-Dihydroxy-24-homovitamin D^ (14) The 5,7-diene (13) (5.8 mg, 0.0113 mmol) was converted, as described for (_11) , to the vitamin analogue (14^) (890 10 yg, 19%). The retention time of (14) under the El'tOH above—described HPLC condition was 11.0 min. UVX : 265 max nm, : 228 nm. MS m/z 430 (M+) , 412, 394 (base peak, 376, 287, 269, 251,152, 134, 59.

If desired, the compounds of this invention can be 15 readily obtained in crystalline form by crystallization from suitable solvents, e.g. hexane, ethers, alcohols, or mixtures thereof as will be apparent to those skilled in the art.

Also if desired the compounds may be acylated according to the standard methods to yield the corresponding partially 20 or completely hydroxy-protected products where each of , R2 and R^ is hydrogen or acyl. For example, treatment of the trihydroxy product with acetic anhydride at room temperature in pyridine yields the 1,3-diacetyl compound whereas at elevated temperatures (75°-100°C) the 1,3,25-25 triacetyl compound is obtained. By analogous methods fully or partially hydroxy-protected derivatives, i.e. derivatives with other acyl groups such as benzoyl, can be obtained. A partially acylated derivative, e.g. 1,3-diacyl may also be further acylated, e.g. at C-25, by a different acyl group 14 to obtain derivatives carrying mixed hydroxy-protecting functions. Selected removal of protecting groups can also readily be accomplished by selective hydrolysis (e.g. 10% KOH/MeOH at room temperature) of a 1,3,25-tri-O-acyl 5 derivatives, to yield 1,3-dihydroxy-25-0-acyl compound. Different protecting groups can then be introduced at the free hydroxy-positions and it is thus obvious that a combination of selective protection/deprotection steps will yield derivatives with any desired combination of hydroxy-10 protecting groups in the product.

Bone calcium mobilization activities of la,25-(OH)^-24-homo-D^ compounds.

Bone calcium mobilization activity was assayed by measuring the rise in serum calcium levels in response to the 15 compound administered. Male, weanling rats (Holtzman Co., Madison, WI) were fed a low-calcium, vitamin D deficient diet (Suda et al, J. Nutr. 100 1049-1050, 1970) and water ad libitum for 3 weeks. The rats were then divided into three groups of 5-6 rats each and were given intrajugularly either 20 1,25-(OH) 2^ or the test compound dissolved in 0.05 ml of 95% ethanol. Rats in the control group were given 0.05 ml ethanol vehicle in the same manner. Eighteen hours after the dose, the rats were killed and their blood was collected and centrifuged to obtain serum. Serum calcium concentrations 25 were determined with an atomic absorption spectrometer Model 403 (Perkin-Elmer Co., Norwalk, Conn.) in presence of 0.1% lanthanum chloride.

Results obtained are shown in the following Table: Table 1 Increase of serum calcium concentration in response to a compound administered Exp.I .Amount Compound Administered Administered (pnpl/rat) Ethanol la,25-(OH),D la, 25-(OH)f-24- harto-D- 650 650 Serum calcium Concentration (mg/100 ml) + * 3.6 ~ 0.3 Zi 4.9 ± 0.2 W 4.4 + 0.2 D} Exp. II Ethanol la, 25-(OH) ~D la, 25- (OH) 2~/2E-dehydro- 23-homo- 325 650 4.2 *0.1 ° .0 + 0.5 f. 5.0 ±0.5 dl * Standard deviation from the means significantly different 20 b) frcxn a) .00Q1 and d) frcm c) It can be concluded frcm the foregoing data that in the vitamin D responsive systems of vitamin D-deficient animals the compounds of this invention exhibited the same activity as 25 la, 25-hydroxyvitamin D^, the circulating hormonal form of the vitamin, although, in the case of the 22-dehydro derivative the dosage was significantly higher.

The compounds of this invention may be readily administered in sterile parenteral solutions by injection or 30 intravenously or by alimentary canal in the form of oral dosages, or by suppository or even transcnjtaneously, for example. Doses of frcm, say, 0.1 ng to about 2.5 ng per day are generally effecrtive in obtaining the physiological calcium balance responses characteristic of Vitamin D-like activity with 35 maintenance dosage of from, say, 0.1 ng to about 0.5 |jg being suitable. 1 / I 0 Dosage forms of the ccnpounds can be prepared by ccmbining them with a non-toxic pharmaceutically acceptable carrier as is well known in the art. Such carriers may be either solid or liquid such 5 lactose, sucrose, peanut oil, olive oil, sesame oil and water. If a solid carrier is used the dosage forms of the ccrnpounds of the invention may be e.g. tablets, capsules, powders, troches or lozenges. If a liquid carrier is used, soft gelatin capsules or syrup or liquid suspensions, enulsions or solutions are typicallly 10 the dosage form. The dosage forms may also contain adjuvants, such as preserving, stabilizing, vetting or emulsifying agents or solution promoters. They may also contain other therapeutically valuable substances.

It should be understood that although dosage ranges are 15 given the particular dose to be administered to a host will depend upon the specific disease state being treated, the end results being sought in a particular case, the physical size of the host, as well as other factors known to those skilled in the art in the therapeutic use of such medicinal agents. i 7 1.

Claims

CLAIMS A compound having the formula where and R^ are each independently hydrogen, acyl 5 having from 1 to 4 carbon atoms or benzoyl and R^ and R_ each represent hydroaen or taken together form a carbon to carbon bond.
2. A compound according to claim 1 wherein R^ , R^ and R3 are hydrogen and R4 and R_ are hydrogen. 10 3. A compound according to claim 1 wherein R^, R^ s hydrogen an; :arbon to carbon bond. and R^ are hydrogen and and R- together represent a 4. rorm. The compound of claim 2 or 3 in crystalline 15 5. A compound according to claim 3 wherein the A22 bond is in the E configuration. 5. A compound according to claim 3 wherein the A22 bond is in the Z configuration. 7. A pharmaceutical composition which comprises at 20 least one compound as claimed in any one of the preceding claims and a oharmaceutically acceptable excipient. 18 8. A compound having the formula wherein each R is independently hydrogen, acyl having from .1 to 4 carbon atoms, benzoyl or methoxymethyl. 5 y. A compound according to claim 8 wherein each R is methoxymethyl. 10'. A compound according to claim 8 wherein each R is hydrogen. 11. A compound according to claim 8 wherein each 10 R is acetyl. 12. a compound having the formula wherein R.^, R2 and R3 are each independently hydrogen, acyl having from 1 to 4 carbon atoms or benzoyl and and R^ represent 15 hydrogen atoms or taken together form a carbon to carbon bond. I 3 13_ A compound according to claim 12 wherein and R2 are each independently acyl having from 1 to 4 carbon atoms or benzoyl. 14. A compound according to claim 12 wherein and 1*2 are both acetyl and R-j is hydrogen. a compound according to any one of claims 12 to 14 wherein R^ and R,- together form a carbon to carbon bond. 16. A compound according to any one of claims ]2 to 14 wherein R^ and Rj- represent hydrogen atoms. 17. Process for converting a OH side chain of a steroid nucleus to a side chain which comprises reacting the starting material with triethyl orthoacetate to provide the ester side chain and reacting the ester with a methyl magnesium halide. 1g. Process according to claim 17 wherein the 20 halide is methylmagnesium bromide. .19. Process according to claim 17 cr 18 wherein the reaction with triethyl orthoacetate is carried out in the presence of propionic acid, as catalyst. 20. Process according to claim 17v substantially as hereinbefore described. F.R. KELLY & CO., AGENTS FOR THE APPLICANTS.