Hydrohydroxymethylation of Ethyl Ricinoleate and Castor Oil

The direct functionalization of the carbon–carbon double bonds of castor oil and its derivatives is of major interest to access biosourced building blocks. In particular, polyol derivatives can be produced in this way and find application in the field of bio-based polyesters and polyurethanes. In this study, we described the synthesis of polyhydroxylated derivatives via a hydrohydroxymethylation reaction consisting of two consecutive Rh-catalyzed reactions: a hydroformylation reaction followed by a hydrogenation reaction of formyl groups. A catalytic system based on Rh­(acac)­(CO)2 and a trialkylamine proved to be active both in hydroformylation of carbon–carbon double bonds and reduction of the resulting aldehydes into primary alcohols. By optimizing the reaction conditions, yields in alcohols of 74 and 80% were reached for castor oil and ethyl ricinoleate, respectively.