Chemical synthesis, spectral properties, and chromatography of 4α-methyl and 4β-methyl isomers of (24R)-24-ethyl-5α-cholestan-3β-ol and (24S)-24-ethyl-cholesta-5,22-dien-3β-ol

Abstract Described herein are chemical syntheses of the following compounds: 4-methyl-(24S)-24-ethyl-cholesta-4,22-dien-3-one, 4,4-dimethyl-(24S)-24-ethyl-cholesta-5, 22-dien-3-one, 4β-methyl-(24R)-24-ethyl-5α-cholestan-3β-ol, 4α-methyl-(24R)-24-ethyl-5α-cholestan-3β-ol, 4α-methyl-(24S)-24-ethyl-5α-cholest-22-en-3β-ol, 4-methyl-6β-bromo-(24S)-24-ethyl-cholesta-4, 22-dien-3-one, 4α-raethyl-(24S)-24-ethyl-cholesta-5, 22-dien-3β-ol, 4α,5α-epoxy-(24S)-24-ethyl-cholesta-4,22-dien-3β-yl acetate, 4β-methyl-(24S)-24-ethyl-cholest-22-en-3β,5α-diol, 4β-methyl-5α-hydroxy-(24S)-24-ethyl-cholest-22-en-3β-yl acetate, 4β-methyl-(24S)-24-ethyl-cholesta-5, 22-dien-3β-yl acetate and 4β-methyl-(24S)-24-ethyl-cholesta-5, 22-dien-3β-ol. Chromatographic, nuclear magnetic resonance, and mass spectral data are presented for the compounds under consideration.