| Popis: |
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 intermediates obtained by the reduction of (R)-arylmethylsuccinic acid mono-methyl esters. |
