Process for producing pyripyropene derivatives and intermediates for the production thereof

Abstract

Disclosed is a process for producing compound C represented by formula C: wherein R' represents straight chain, branched chain, or cyclic Calkylcarbonyl, wherein Ris used as a protective group for hydroxyl at the 7-position of compound C. Rrepresents formyl; optionally substituted straight chain Calkylcarbonyl; optionally substituted benzyl; group —SiRRRoptionally substituted by halogen atom wherein R, R, and Reach independently represent straight chain or branched chain Calkyl or phenyl; Calkyloxy-Calkyl optionally substituted by halogen atom; Calkylthio-Calkyl optionally substituted by halogen atom; straight chain, branched chain, or cyclic Calkyl optionally substituted by halogen atom, provided that, when alkyl in the Calkyl group is of a branched chain or cyclic type, the alkyl group is Calkyl; Calkenyl optionally substituted by halogen atom; Calkynyl optionally substituted by halogen atom; or an optionally substituted saturated or unsaturated five- or six-membered heterocyclic group. The process can produce pyripyropene derivatives that have acyloxy groups at the 1- and 11-positions and a hydroxyl group at the 7-position and are useful as insect pest control agents at a high yield.