P. Yates, R. Grewal, P. Hayes
Nov 1, 1988
Citations
0
Influential Citations
22
Citations
Journal
Canadian Journal of Physiology and Pharmacology
Abstract
Reduction of dimethyl 3-hydroxy-4,4,8-trimethyl-6-oxo-cis-bicyclo[3.3.0]octa-2,7-diene-1,2-dicarboxylate (8) with lithium and ammonia gives dimethyl 3-hydroxy-4,4,exo-8-trimethyl-6-oxo-cis-bicyclo[3.3.0]oct-2-ene-1,2-dicarboxylate (9), which on acetylation, reduction with sodium borohydride, and methanolysis gives dimethyl 3,exo-6-dihydroxy-4,4,exo-8-trimethyl-cis-bicyclo[3.3.0]oct-2-ene-1,2-dicarboxylate (12). This on 2-decarbomethoxylation followed by treatment with lithium acetylide in the presence of cerium trichloride gives methyl 3-ethynyl-3,exo-6-dihydroxy-4,4,exo-8-trimethyl-cis-bicyclo[3.3.0]octane-1-carboxylate (21), which on hydration, diacetylation, and treatment with tri-n-butyltin hydride and azoisobutyronitrile is converted to methyl exo-6-acetoxy-3-acetyl-4,4,exo-8-trimethyl-cis-bicyclo[3.3.0]octane-1-carboxylate (31). Methanolysis of 31. tert-butyldimethylsilylation, and reaction with potassium tert-butoxide in tert-butyl alcohol gives exo-4-tert-butyldimethylsilyloxy-exo-2,6,6-trimethyl[...