Novel regioselective hydrogenation of alkadienoic acids caused by the addition of water

Article abstract of DOI:10.1016/S0040-4039(00)61142-5

The regioselective hydrogenation of 3,8-nonadienoic acid to 8-nonenoic acid was realized by the addition of water with RhCl[P(p-tolyl)3]3 in benzene at 1 atm hydrogen, whereas in the absence of water the reaction mostly gave 3-nonenoic acid. The novel selectivity is caused by both an accelerating effect of water on the hydrogenation of the 3-position and a retarding effect on that of the 8-position.