Utilization of a Michael addition: Dipolar cycloaddition cascade for the synthesis of (+/-)-cylindricine c

摘要

[GRAPHICS] A new approach to the marine alkaloid (+/-)-cylindricine C has been devised. The key element of the synthesis consists of a Michael addition/dipolar cycloaddition cascade between 2,3-bis(phenyisulfonyl)-1,3-butadiene and 9-triisopropylsilanyloxy-non-l-en-5-one oxime. The resulting cycloadduct was converted into (+/-)-cylindricine C by a sequence of reactions including a reductive cyclization, intramolecular enolate alkylation, and conjugate addition to introduce the n-hexyl side chain.