Abstract
Some mesembrine type (3a-aryl-cis-octahydroindol-6-one) compounds (VIII-X) were synthesized from benzyl nitriles (I) by the six-step sequence of the reactions involving an acid-catalyzed cyclization of 3a-aryl-[2-(2-methyl-1, 3-dioxolan-2-yl) ethyl]-1-pyrroline (VI). Pictet-Spengler reaction of XVIII and XIX, which were derived from N-benzyl derivative (Xb), gave dihydrocrinine models (XX and XXI) in good yields. The stereochemistry of two epimeric 3a-phenyl-cis-octahydroindol-6-ols (XIVa and XVIa) was determined on the basis of infrared and nuclear magnetic resonance spectral data.
