Stereoselective Synthesis of Bicyclic Lactones Via Annelation Protocol

A successful two-step annelation protocol of diesters and methyl bromoacetate with 2- chlorocyclopentanone derivatives was efficiently pursued, which gave suitably substituted bicyclic lactones in high overall yields and with complete streoselectivity mediated by K-Selectride and Wilkinsons catalyst, is reported. As part of a program aimed at rapid synthesis of bicyclic lactones which inherently occurs in many active natural products, this paper has shown a novel and rare methods for the synthesis of these important compounds based on alkylation of cyclopentanone derivatives and further demonstrate efficient reduction protocol of these compounds to the bicyclci lactones