Hydrogenolysis thioester

Hydrogenolysis of carboxylic acid thioesters over Ra-Ni deactivated by boiling in acetone is one of the classic syntheses of aldehydes.405-408 Without deactivation the Ra-Ni hydrogenolyzes the thioesters to alcohols. 

Thiol esters undergo smooth reduction to give aldehydes by the Fukuyama hydrosilylation procedure, which is an alternative way to transform carboxylic acids to aldehydes. Upon treatment with Et3SiH and 10% Pd/C, a thioester underwent smooth reduction to give an aldehyde.409,410 For example, to a stirred mixture of thioester and Pd/C in acetone may be added Et3SiH at room temperature under an Ar atmosphere. Stirring is continued until the hydrogenolysis is complete (0.5-1 h) (Scheme 4.117). 

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