TRANSFORMATION OF ORGANIC-COMPOUNDS IN THE PRESENCE OF METAL-COMPLEXES .7. SELECTIVE REDUCTION OF DIKETONES BY HYDROSILYLATION IN THE PRESENCE OF RHODIUM(I) COMPLEXES

An investigation was made of the hydrosilylation of 2,2,4,4-tetramethy l-1,3-cyclobutanedione with alkyl- and arylsilanes, catalyzed by a var iety of rhodium(I) complexes. The selectivity of the reduction depends strongly on the steric requirements of the silane molecules. An appro priate selection of hydrosilanes (di- and certain trialkylsilanes) pro vides a new selective method for the preparation of 3-hydroxy-2,2,4,4- tetramethylcyclobutanone. Diphenylsilane and amylsilane are selective in the formation of isomeric diols, diphenylsilane favouring formation of the cis-diol, and amylsilane yielding mainly the trans-diol.