Improved process for synthesis of 5-alpha-cholest-8(14)-en-3 beta-ol-15-one and other 15-oxygenated sterols

• Main Authors: WILSON, WILLIAM K, WANG, KER-SHI, KISIC, ALEMKA, SCHROEPFER, GEORG J., JR
• Format: Patent
• Language: English; French; German
• Published: 14.09.1994
• Edition: 5
• Subjects: CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY; STEROIDS

A process for preparing 15-oxygenated sterols, such as 3 beta -hydroxy-5 alpha -cholest-8(14)-ene-15 one, comprising converting 7-dehydrocholesterol to 3 beta -benzoyloxycholesta-5,7-diene, converting the 3 beta -benzoyloxycholesta-5,7-diene to a 3 beta -benzoyloxy-5-cholesta-7,14-diene, converting the 3 beta -benzoyloxy-5-cholesta-7,14-diene to a 3 beta -benzoyloxy-14 alpha , 15 alpha -epoxy-5-cholest-7-ene and converting the 3 beta -benzoyloxy-14 alpha , 15 alpha -epoxy-5-cholest-7-ene to a 15-oxygenated sterol. Preferably, the 3 beta -benzoyloxy-cholesta-5,7-diene is converted to a 3 beta -benzoyloxy-5-cholesta-7,14-diene by (i) contacting 3 beta -benzoyloxy-cholesta-5,7-diene, in a solvent at a temperature of at most about -55 DEG C, with HCl at a concentration of at least about 2.0 M for a time sufficient to convert the 3 beta -benzoyl-oxycholesta-5,7-diene to a 3 beta -benzoyloxy-5-cholesta-7,14-diene; (ii) neutralizing the resultant reaction mixture with a base to prevent formation of a significant amount of 3 beta -benzoyloxy-5-cholesta-8,14-diene; and (iii) recovering the 3 beta -benzoyloxy-5-cholesta-7,14-diene.