The α-alk-1-ynylation of β-dicarbonyl compounds and nitronate salts by alk-1-ynyl-lead triacetates

Abstract

Di(alk-1-ynyl)mercury compounds and alk-1-ynyltrimethylstannanes have been shown to react with lead tetra-acetate to give alk-1-ynyl-lead triacetates, unstable intermediates which may be used for the C-alkynylation of β-dicarbonyl compounds and the salts of nitroalkanes. A comparative study of the two methods has shown that the tin–lead exchange route to the alkynyl-lead intermediate results in better yields, and in an examination of the scope of this alkynylation procedure the acetylene derivatives (5), (9)–(14), (27)–(30), (32), (34), (36)–(41), (43), (45), (47)–(49), and (51)–(56) have been produced in moderate to good yields.