Ruthenium-Catalyzed Cyclic Carbonylation of Allenyl Alcohols. Selective Synthesis of γ- and δ-Lactones

Abstract

[reaction: see text] Ruthenium complex-catalyzed carbonylation of allenyl alcohols quantitatively gave cyclic carbonyl compounds, gamma- and delta-lactones, in which the hydroxy group of allenyl alcohols participated in the cyclization. A wide variety of allenyl alcohols, such as mono-, di-, and trisubstituted alcohols, can be used in this reaction to produce 3- and 4-substituted gamma-lactones. Similarly, the cyclic carbonylation of 3,4-pentadien-1-ol 10a and 2-methyl-4,5-hexadien-2-ol 11a gave delta-lactones, 5,6-dihydro-3-methyl-2H-pyran-2-one 10b, and 5,6-dihydro-6,6-dimethyl-3-methyl-2H-pyran. 2-one 11b, respectively, in a quantitative yield.