Intramolecular asymmetric Pummerer reactions as a key step in the synthesis of bicyclic precursors of anthracyclinones
作者:Jose Luis Garcı́a Ruano、Cristina Garcı́a Paredes
DOI:10.1016/s0040-4039(99)02025-0
日期:2000.1
Highly stereoselective Pummerer reactions were observed on reaction of β-hydroxysulfoxides 2a–2d and 2′b with TMSOTf. Sulfenium intermediates are captured intramolecularly by the electrophilic aromatic ring, thus yielding bicyclic structures with a p-tolylsulfenyl group at the benzylic position in a cis arrangement with respect to the hydroxyl group. The stereogenicity transfer seems to be mainly controlled