Two-step synthesis of alpha-hydroxy-gamma-substituted gamma-lactones via Ru(II)-catalyzed addition of trimethylsilyl alpha-polychlorocarboxylates or its parent acids to olefins

alpha-Hydroxy-gamma-butylrolactones are known to increase the food intake o f experimental rats. We have synthesized several new members of this group including alpha-hydroxy-gamma-hexyl-gamma-butyrolactone in high yields by R uCl2(PPh3)(3)-catalyzed reaction of alpha-chlorinated carboxylic acids with 1-alkenes, followed by hydrolysis with aqueous potassium carbonate (1 mol dm(-3)). While decreased food intake was, in fact, observed the rats quickl y regained their appetites within about twenty-four hours of injection. Seven new alpha-chloro-gamma-aryl-gamma-butyrolactones were also synthesize d by the reaction of trimethylsilyl dichloroacetate or trimethylsilyl 2,2-d ichloropropionate with arylacetylenes in the presence of the ruthenium(II) catalyst.