Reactivity of substituted and unsubstituted diphenylphosphonium diylides towards carbonic acids derivatives

Article abstract of DOI:10.1016/S0040-4020(97)10360-X

In order to further delimit the scope of application of diphenylphosphonium diylides, their reactivity towards carbonic acid derivatives was investigated. Non-stabilized diylides react with ethyl carbonate to give new monoylide intermediates which lead, by in situ Wittig reaction with carbonyl compounds, to the synthesis of α,β-unsaturated esters or acids the double bond being di- or trisubstituted. The reaction proceeds in mild conditions and with high E stereoselectivity. Stabilized diylides are inactive towards carbonates but semi-stabilized diylides react with ethyl carbonate leading to the synthesis of non-functionalized alkenes instead of the α,β-unsaturated esters or acids.