SELENIUM STABILIZED CARBANIONS - ALPHA-LITHIO SELENOXIDES AS REAGENTS FOR THE SYNTHESIS OF OLEFINS, ALLYL ALCOHOLS, AND DIENES

Techniques for the preparation of α-lithio selenoxides have been developed. These reagents react cleanly with most aldehydes and ketones to give β-hydroxy selenoxides, which can be thermolyzed to allyl alcohols or reduced to β-hydroxy selenides. The β-hydroxy selenides are further transformed to olefins by reductive elimination. α-Lithio selenoxides can also be alkylated and acylated, although these reactions are of lesser scope and usefulness than the reaction with aldehydes and ketones. A synthesis of 1,1-bis(phenylseleno)cyclopropane was developed based on an intramolecular alkylation of an α-lithio selenoxide. The compound is a suitable precursor for the preparation of 1-phenylselenocyclopropyllithium, which was used to prepare cyclopropyl phenyl selenide and 1-phenylselenocyclopropanecarboxylic acid. © 1979, American Chemical Society. All rights reserved.