Optically pure (R)-arylmethylsuccinic acid mono-methyl esters were obtained efficiently by using the catalytic asymmetric hydrogenation of arylidenesuccinic acid monoesters with a rhodium (I) complex of a chiral bisphosphine,(4S, 5S)-MOD-DIOP. Asymmetric total syntheses of some naturally occurring lignans,(+)-collinusin,(−)-deoxypodophyllotoxin, and (+)-neoisostegane, were achieved via several steps from (R)-γ-butyrolactones as key ...