title: A straightforward synthesis of cyclobutenones via a tandem Michael addition/cyclization reaction of 2,3-allenoates with organozincs.
abstract: An efficient method for synthesis of polysubstituted cyclobutenones, which are not readily available from traditional methods due to the intrinsic ring strain, is described. The reaction of 2,3-allenoates and organozinc reagents proceeds via a tandem Michael addition/cyclic 1,2-addition/elimination mechanism with the functional groups from the organozinc reagents being introduced to the 3-position of the cyclobutenone products regiospecifically in moderate to excellent yields. Application to the synthesis of stereodefined β,γ-unsaturated enones is demonstrated.
authors.affiliation: Laboratory of Molecular Recognition and Synthesis, Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, PR China.
authors.forename: Guobi
authors.initials: G
authors.lastname: Chai
authors.forename: Shangze
authors.initials: S
authors.lastname: Wu
authors.forename: Chunling
authors.initials: C
authors.lastname: Fu
authors.forename: Shengming
authors.initials: S
authors.lastname: Ma