The Lewis acid-catalyzed intramolecularsubstitutionreactions of 4-vinyloxy- or 4-acyloxy-azetidin-2-ones with nitrogen-bound allyl-, propargyl- and vinyl-silanes leading to the carbacephams or carbacephems, are reported. The formation of carbapenams was not observed. To illustrate the potential of these reactions to be carried out under solid-phase conditions, a synthesis of diastereomeric 5-vinyl-carbacephams
Functionalised Allylsilanes from Silylcopper Reagents and Allene. A Useful Strategy for Cyclopentane Annulations
作者:Asuncion Barbero、Carlos Garcı&#x;a、Francisco J. Pulido
DOI:10.1016/s0040-4020(00)00129-0
日期:2000.4
allylsilane-containing divinyl ketones and oxoallylsilanes, respectively. They undergo highly stereocontrolled silicon-assisted intramolecular cyclizations when treated with protic or Lewis acid leading to cyclopentane ring-formation.