Lithiated N-substituted 1, 2, 4-triazoles 3 and 8 and benzimidazole 11 reacted with (1R)- fenchone to give derivatives 5c, 9 and 12 in good yields as single diastereoisomers.(S)- Lactic acid 16 reacted with o-phenylenediamine 15 to give optically pure (S)-2-(1- hydroxyethyl) benzimidazole17 (85%). Ring closures converted the fenchone derivative 12 into novel tricyclic fused benzimidazoles 13 and 14, and converted oxazolidine derivative ...