@article{a634c3f656634d81890b7d56ff88e5a9,
title = "Steroids and related natural products. Part XLII. 14α-Methyl cholestanes",
abstract = "Oxygenation of the 14α-methyl group in 3β-acetoxy-7α- hydroxy-14α-methyl-5α-cholestane has been achieved by reaction with lead tetra-acetate. Cleavage of the resulting 7α,32-epoxide with pyridine hydrochloride in refluxing acetic anhydride gave 3β-acetoxy-14α- acetoxymethyl-5α-cholest-7-ene, while chromium trioxide in acetic acid afforded the lactol derived from 3β-acetoxy-7-oxo-5α-cholestane- 14α-carboxylic acid.",
author = "Knight, {John C.} and Belletire, {John L.} and George Pettit",
note = "Funding Information: wt. of 500 (Found: C, 77.0; H, 10.4. C32H5204 requires C, 76.75; H, 10.45; M , 500). The most polar zone (G) of the original chromatogram yielded a solid which was crystallised twice from methanol to give needles (100 mg.) of starting material (XII), m. p. and mixed m. p. 133-135{"}. Chromium Trioxide Oxidation of 3P-Acetoxy-7cc,32-epoxy- 30,31-dinorZanostane (XII) .-Cyclic, ether (XII) (175 nig.) was dissolved in acetic acid (20 ml.) and the solution heated to 60{"}. Jones reagent was rapidly added with stirring until an orange tinge appeared. Excess reagent was immediately destroyed by addition of methanol. The hot solution was poured on to crushed ice and diluted with water, and ex- tracted with diethyl ether. The ethereal extract was washed well with water and sodium hydrogen carbonate solution. Evaporation to dryness yielded a colourless solid, which crystallised from acetone-light petroleum, giving silky white needles (60 mg.) of Zactol (XV) (R1 = Ac, R2 = H), m. p. 223-225{"}, [%ID -24.7{"} (c 1.21); v,,,. 1775 cm.-l (y-lactol), 1733 and 1268 cm.-l (acetate) (CHCl,) ; J. Chem. SOC. (C), 1967 the mass spectrum displayed a molecular ion a t m/e 488, correct for C,,H4,0B, and the n.m.r. spectrum showed 6 2.13 (3-OAc). On heating under reflux for 45 min. in methanol (20 ml.) containing perchloric acid (2 drops), the lactol (XV) (50 mg.) was converted to acetal (XV) (R1 = H, R2 = Me) (45 mg.) with simultaneous cleavage of the 3P-ace- tate. The acetal crystallised from aqueous methanol as needles, m. p. 153-155{"}, vmx. 1775 cmF1 (y-lactol), n.m.r. spectrum 6 3-40 (methoxy); the mass spectrum showed a molecular ion a t in/e 460 (Found: C, 75.6; H, 10.95. C29H4804 requires C, 75-6; H, 10.5; M , 460). Acetylation of the acetal (XV; R1 = H, R2 = Me) gave an oily acetate, (XV; R1 = Ac, R2 = Me) which exhibited vmax. 1775 cm.-l (y-lactol) and 1730, 1265 cmF1 (acetate); n.m.r. 6 2.02 (acetate) and 3.32 (methoxy). This investigation was supported by a National Science Foundation grant, Public Health Service Research Grants and by the U.S. Atomic Energy Commission. [7/620 Received, May 19th, 19671",
year = "1967",
doi = "10.1039/J39670002427",
language = "English (US)",
pages = "2427--2432",
journal = "Journal of the Chemical Society C: Organic Chemistry",
issn = "0022-4952",
publisher = "Chemical Society",
}