Synthesis of the marine epoxy sterol 9 alpha,11 alpha-epoxy-5 alpha-cholest-7-ene-3 beta,5,6 beta-triol.
The synthesis of 9 alpha,11 alpha-epoxy-5 alpha-cholest-7-ene-3 beta,5,6 beta-triol (1), a highly oxygenated marine sterol containing a 9,11-epoxide moiety in the nucleus, is described. Epoxy sterol 1 was synthesized from cholesta-5,7-dien-3 beta-ol. Oxidation of this sterol with m-chloroperbenzoic acid followed by hydrolysis and acetylation furnished 5 alpha-cholest-7-ene-3 beta,5,6 alpha-triol 3,6-diacetate (2). Mercuric acetate dehydrogenation of diacetate 2, followed by oxidation with manganese dioxide and epoxidation with m-chloroper-benzoic acid, afforded 9 alpha,11 alpha-epoxy-3 beta,5-dihydroxy-5 alpha-cholest-7-en-6-one (5). Reduction of 5 with lithium aluminum hydride gave the desired compound 1. The structures of all synthetic intermediates were confirmed by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. A reassignment of resonances for carbons 1, 8, and 15 in the 13C NMR spectrum of 1, based on 2D-NMR correlation spectroscopy, has been accomplished.
Migliuolo
A
A
Dipartimento di Chimica Organica e Biologica, Università di Napoli, Italy.
Notaro
G
G
Piccialli
V
V
Sica
D
D
D000107:Acetylation; D000535:Aluminum; D017607:Aluminum Compounds; D002723:Chlorobenzoates; D002782:Cholestenes / Q000138:chemical synthesis* / Q000737:chemistry; D006868:Hydrolysis; D008094:Lithium; D018020:Lithium Compounds; D009682:Magnetic Resonance Spectroscopy; D008345:Manganese; D017895:Manganese Compounds; D008628:Mercury; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010087:Oxides
D017607:Aluminum Compounds; D002723:Chlorobenzoates; D002782:Cholestenes; D018020:Lithium Compounds; D017895:Manganese Compounds; D010087:Oxides; C036427:3-chlorobenzoic acid; C059540:9,11-epoxycholest-7-ene-3,5,6-triol; D008345:Manganese; C042073:lithium aluminum hydride; D008094:Lithium; D000535:Aluminum; D008628:Mercury; C029823:mercuric acetate; C016552:manganese dioxide