Through ring-closure reactions of N-or 1′-substituted 1-(2′-aminoethyl)-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinolines (5a-e) with phenylphosphonyl dichloride, 1-or 3-substituted 4- phenyl-1, 3, 4, 6, 7, 11b-tetrahydro-2H-1, 3, 2-diazaphosphorino [6, 1-a] isoquinolin-4-one diastereomers (7a–e and 8a–c, e), the first representatives of a new ring system, were prepared. The diastereomeric ratios in the cyclizations and the conformer (A–E) ...
