Strained Azetidinium Ylides: New Reagents for Epoxidation.

Abstract

Oxirane derivatives R 0030Strained Azetidinium Ylides: New Reagents for Epoxidation. -Azetidinium ylides, generated by deprotonation of the corresponding azetidinium salts, effect epoxidation of aldehydes (I) and ketones such as (V) in a diastereoselective manner. Tri-and tetrasubstituted epoxides are obtained that are unattainable via classical ammonium ylide chemistry. The trisubstituted oxiranes (III) give rise to an unexpected rearrangement producing pyrrolidin-3-ones having a quaternary carbon center. -(ALEX, A.; LARMANJAT, B.; MARROT, J.; COUTY, F.; DAVID*, O.; Chem. Commun. (Cambridge) 2007, 24, 2500-2502; Inst. Lavoisier, CNRS, Univ. Versailles St. Quentin, F-78035 Versailles, Fr.; Eng.) -M. Paetzel 44-092