Studies on electrophilic addition reaction of 2,3-allenoates with PhSeCl

beta-Organoselenium substituted butenolides were prepared from 2,3-allenoates and PhSeCl in the presence of water. The yields of the products depend largely on the structures of 2,3-allenoates. The addition of water is crucial for some of this electrophilic cyclization. The reaction of simple unsubstituted methyl 2,3-butadienoate afforded methyl 4-chloro-3-phenylselanylbut-2(Z)-enoate in good yield and stereoselectivity. (c) 2006 Elsevier Ltd. All rights reserved.