Ring-Closing Metathesis in the Synthesis of BC Ring-Systems of Taxol
Résumé
BC ring-systems of taxol with different or no protecting group for the C1,C2 diol moiety have been efficiently synthesized. The 8-membered B ring is formed by a ring-closing metathesis (RCM) between the C10 and C11 carbons. The influence of the 1,2-diol protecting group on the RCM reaction has been studied in details.