(R)-2-alkoxycarbonyl-1-formyl-1,2,3,4-tetrahydro-6,7-dimethoxyisoquinolines from D -(–)-tartaric acid: synthesis of (S)-homolaudanosine and (S)-2,3,9,10,11-pentamethoxyhomoprotoberberine

The title aldehydes were prepared from D-(–)-tartaric acid and their utility in the asymmetric synthesis of phenylethylisoquinolines demonstrated by the preparation of (S)-homolaudanosine and (S)-2,3,9,10,11-pentamethoxyhomoprotoberberine.