Microbial reduction of 7-methoxycarbonyl bicyclo[4. 3. 0]non-3-en-8-one ((±)-3) afforded the optically active (-)-3, which was efficiently converted by ring contraction using thallium (III) nitrate to the intermediate (11) used to synthesize carbacyclin (1).
Both enantiomers of C2-symmetric dimethyl 3,7-dioxo-cis-bicyclo[3.3.0]-octane-2,6-dicarboxylate (3) were prepared in enantiomerically pure form by the lipase-catalyzed demethoxycarbonylation, respectively. An expeditious formal total synthesis of (+)-carbacyclin using this hybrid process was done.
Both enantiomers of C-2-symmetric dimethyl 3,7-dihydroxybicyclo[3.3.0]-octa-2,6-dicarboxylate 3 were prepared in enantiomerically pure form from symmetric tetraester 1 by the lipase-catalyzed demethoxycarbonylation, respectively. Double asymmetric differentiation with lipase in the above demethoxycarbonylation was observed. Their applications to formal total syntheses of (+)-carbacyclin and (-)-ajmalicine including (-)-tetrahydroalstonine are also described. (C) 1998 Elsevier Science Ltd. All rights reserved.
Xie, Z.-F.; Suemune, H.; Funakoshi, K., Journal of the Chemical Society. Perkin transactions I, 1991, # 12, p. 3087 - 3090
作者:Xie, Z.-F.、Suemune, H.、Funakoshi, K.、Oishi, T.、Akita, H.、Sakai, K.