An Effective and Selective Conjugate Propargylation Reaction of Stannylallenes to α,β-Unsaturated Carbonyl Compounds and α-Nitro Olefins

Article abstract of DOI:10.1021/jo00303a019

Stannylallenes (1) reacted with α,β-unsaturated carbonyl compounds and α-nitro olefins in the presence of TiCl4 to give the corresponding conjugate propargylation products.Thus, the reaction of 1 with cyclic and acyclic α,β-unsaturated carbonyl compounds (2) gave β-propargylic ketones (3) in high yields.With α-nitro olefins (4), two types of products, β-propargylic nitroalkanes (5) and α-propargylic ketones (6), were obtained selectively depending on the presence or absence of the α-substituent of 4.Transformation of the products (6) to cyclopentenone derivatives (10 and 12) are also described.