The first total synthesis of lembehyne B

The total synthesis of lembehyne B was accomplished in five steps in 51% total yield. The cross-cyclomagnesiation of two allenic components, nonadeca-1,2-diene and pentadeca-13,14-dien-1-ol tetrahydropyranyl ether, with EtMgBr in the presence of Mg and Cp₂TiCl₂ catalyst (10 mol%) was used in the key step of the synthesis.