Oxidative polycyclization with rhenium(VII) oxides: application of the stereoselectivity rules in the total synthesis of rollidecins C and D

Rollidecin C, 1, and rollidecin D, 2, two adjacent bis-THF Annonaceous acet ogenins, were synthesized from the partially functionalized 'naked' carbon skeletons 14 and 15, respectively. The retrosynthetic route to the target c ompounds was guided by the recently proposed rules of stereoselectivity for the tandem oxidative cyclization reaction with trifluoroacetylperrhenate. Thus, the rapid transformation of compounds 14 and 15 to 1 and 2, respectiv ely, was achieved with a predictable stereochemistry by the oxidative-bis-c yclization with Re(VII) followed by one or two simple transformations. (C) 2001 Elsevier Science Ltd. All rights reserved.