Bicyclo-systems, Tricyclanes, and Quadricyclanes

Clausantalene, a new sesquiterpene from Clausena indica, has the structure (438). The preparation and determination of absolute rotations and configurations of 6,7-dimethoxy-l,2-dimethyl-exo-2-benzonorbornenyl derivatives have been reported. The strategy involved the preparation of 6,7-dimethoxybenzonorbornadiene 

Fujila,T. Nakamura, K. Matsui, and T. Shono, Tetrahedron Letters, 1975, 2441,4385. 

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