Asymmetric Syntheses of 1-Alkyltetrahydro-β-carbolines and a 9- Thio Analogue.

Tetrahydro-β-carbolines, (S)-tetrahydroharman (8a) and (S)-1-phenyltetrahydro-β-carboline (8b), were asymmetrically synthesized starting from (R)-phenylglycinol and 1-benzyl-3-(2-bromoethyl)indole (1). Asymmetric synthesis of the 9-thio analogue (15) of 8a was also achieved.