HIGHLY EFFICIENT METHOD FOR CORIOLIN SYNTHESIS

Formal total synthesis of coriolin has been accomplished on the basis of a [3+2] cycloaddition reaction of a vinylsulfide with 3-(methylthio )-2-siloxyallyl cation. A five-membered vinylsulfide as a C ring unit was prepared in five steps from commercially available compounds. The first [3+2] cycloaddition reaction gave the BC ring intermediate, whic h was then converted into a bicyclic vinylsulfide in three steps. The construction of the A ring by the second [3+2] cycloaddition reaction followed by two-step-conversion afforded the tricyclic enone (30% over all yield from isobutyronitrile) which has previously been synthesized and converted into coriolin. Copyright (C) 1996 Elsevier Science Ltd