A useful synthesis of α,β-bis(methylseleno)alkanes and α,δ-bis(methylseleno)alk-2-enes by the reactions of alkenes and 1,3-dienes with B(SeMe)3-Lewis acid

Reactions of tris(methylsenleno)borane-SnCl₄ with alkenes 1a–g gave α,β-bis(methylseleno)alkanes 2a –g, stereospecifically, and reactions with 1,3-dienes 1i–k afforded α,β-bis(methylseleno)alk-2-enes 2i–k , regioselectively.