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.
                                    在
水的存在下,由2,3-
脲基
甲酸酯和PhSeCl制备β-Organoselenium取代的
丁烯化物。产品的产率主要取决于2,3-烯丙基酯的结构。加
水对于某些亲电环化至关重要。简单的未取代的2,3-
丁二烯酸甲酯的反应以良好的收率和立体选择性提供了4-
氯-3-苯基
硒基
丁酸2-(Z)-烯酸甲酯。