A Method for the Late-Stage Formation of Ketones, Acyloins, and Aldols from Alkenylstannanes: Application to the Total Synthesis of Paecilonic Acid A

Angewandte Chemie - International Edition

4 years ago

A Method for the Late-Stage Formation of Ketones, Acyloins, and Aldols from Alkenylstannanes: Application to the Total Synthesis of Paecilonic Acid A

Heiko Sommer, James Y. Hamilton, Alois Fürstner

Treatment of alkenylstannanes with Cu(OAc)2/Et3N affords the corresponding enol esters or ketones under conditions that proved compatible with many common functionalities; these include groups that would neither survive under the standard Tamao–Fleming conditions for the oxidation of Csp2 −SiR3 bonds nor under the conditions commonly used to oxidize C−B bonds. Chiral centers adjacent to the unveiled carbonyls are not racemized and competing protodestannation is marginal, even if the substrate carries unprotected −OH groups as internal proton sources. Therefore, the procedure is well suited for the preparation of acyloin and aldol derivatives. These enabling virtues are illustrated by a concise approach to the bicyclic lipid paecilonic acid A. Take (it) off: Treatment of alkenylstannanes with Cu(OAc)2/Et3N affords ketones, acyloins, aldols, and enol derivatives under conditions that proved compatible with many common functionalities; these include groups that would neither survive under the standard Tamao–Fleming conditions for the oxidation of Csp2 −SiR3 bonds nor under the conditions commonly used to oxidize C−B bonds. These virtues are illustrated by a concise approach to the bicyclic lipid paecilonic acid A.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/anie.201701391