the synthesis of annulated alkylidene butenolides

In this project the synthesis of annulated alkylidene butenolides were investigated with the use of cyclic 1,2-diketone. The possible synthesis of a butenolide via a intramolecular wittig reaction was investigated. The treatment of a enolate with bromo-acetyl bromide delivered a bromo ester, which gave a phosphonium salt after treatment with triphenylphosphine. In the case of the synthesis of butenolides, the condensation of enolate with phosphonate, after nucleophilic attack of the enolate on the ester group of the phosphonate followed by an intramolecular Horner condensation, the butenolide was delivered as primary product. A butenolide was also obtained with a 65% yield via an intramolecular wittig condensation of a phosphonium salt