The heterogeneously catalyzed diastereoselective hydrogenation
of furan-2-carboxylic acid derivatives modified with chiral auxiliaries
is described. Chiral auxiliaries, catalysts, solvents, and additives
were optimized for the reaction. Finally, the hydrogenation of furan-2-yl-[(S)-2-(hydroxydiphenylmethyl)-pyrrolidin-1-yl]-methanone
resulted in a high diastereoselectivity.
Removal of the auxiliary gave the tetrahydrofuran-2-carboxylic acid
in 95% ee.
heterogeneous catalysis - stereoselective hydrogenation - furans - heterocycle - chiral auxiliary