2. (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 Zbigniew Czarnocki,David B. MacLean,Walter A. Szarek J. Chem. Soc. Chem. Commun. 1987 493