Cobalt carbonyl catalyzed reactions of esters and lactones with hydrosilane and carbon monoxide. A novel synthetic method for the introduction of the siloxymethylidene group
monoxide took place except for bridgehead alkyl acetates. The mechanism of the catalytic reaction has been proposed, and the importance of the silycobalt carbonyl, R/sub 3/SiCO(CO)/sub 4/, as the key catalyst species has been suggested. The high affinity of the silicon in R/sub 3/SiCo(CO)/sub 4/ toward the oxygenatom in the ester is suggested to be the driving force for the formation of alkylcobalt carbonyls