Origins of Regio- and Stereoselectivity in Additions of Phenylselenenyl Chloride to Allylic Alcohols and the Applicability of These Additions to a Simple 1,3-Enone Transposition Sequence

Article abstract of DOI:10.1021/jo00346a022

The regio- and stereoselectivity of phenylselenenyl chloride additions to allylic alcohols and their derivatives have been systematically studied.On the basis of the results, a mechanism involving two basic premises is proposed.These are as follows: (a) allylic oxygen's direct selenonium ion formation to the syn face of the double bond; (b) axial attack of the chloride ion is kinetically favored over equatorial attack.A series of rules which are useful for predicting the regio- and stereoselectivity of phenylselenenyl chloride additions to allylic systems are discussed.In addition, these reactions can be used as the key step in a general 1,3-enone transposition sequence.Several examples of this transposition sequence are illustrated.