Stereochemical course of ring formation in fumitremorgin B and verruculogen, metabolites of Penicillium verruculosum: investigation into the loss of stereochemical integrity of the geminal methyl groups

Abstract

Incorporation studies of [2-²H₃,2^–13C]acetate and different (²H,¹³C)-labelled rnevalonolactones into verruculogen established the stereochemical course of ring C formation in fumitremorgin B, which results in the loss of stereochemical integrity of the C-22 methyl groups, and of the formation of the eight-membered peroxide ring at C-25 in verruculogen.