Palladium-catalyzed asymmetric Wagner-Meerwein Shift: Ring expansion of allenylcyclobutanols

ORGN 262

Barry M. Trost, bmtrost@stanford.edu and Jia Xie, jiaxie@stanford.edu. Department of Chemistry, Stanford University, 337 Campus Drive, Stanford University, Stanford, CA 94305-5080
In this study, we developed a palladium-catalyzed atom economic asymmetric Wagner-Meerwein shift of allenylcyclobutanol substrates. It is an excellent method for creating functionalized cyclopentanones with an á-chiral O-tertiary center by ring expansion of allenylcyclobutanols. This reaction was initiated by hydropalladation and afforded excellent enantioselectivity as well as atom economy. This method provides an efficient route toward the synthesis of natural products such as trans-kumausyne's family, spiro ring systems. In addition, we obtained excellent diastereoselectivity and enantioselectivity at the same time by using 3-monosubstituted allenylcyclobutanols.

 

Asymmetric Reactions and Syntheses
8:00 AM-11:40 AM, Monday, 11 September 2006 Moscone Center -- Room 131, Oral

Division of Organic Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006