Reactions of Dimethyl (2'-Oxopropylidene)Propanedioate and Dimethyl (3'-Bromo-2'-oxopropylidene)propanedioate, Two Highly Electrophilic Trisubstituted Alkenes

Abstract

The keto diester, dimethyl (2'-oxopropylidene)propanedioate, and its new 3'-bromo derivative have been made to react with a variety of nucleophilic reagents. Low molecular weight products have been obtained efficiently by processes involving conjugate addition, Diels-Alder reaction, Diels-Alder reaction having inverse electron demand, or ene reaction. Regiochemistry of the reactions is controlled by the dominant withdrawing effect of the two geminal ester groups. The amine addition products of the bromo keto diester were found to undergo a novel secondary dehydrobromination reaction under alkaline conditions.