A novel synthesis of chiral 1-allyl-1,2,3,4-tetrahydro-β-carboline employing allyltributyltin and chiral acyl chlorides

β-Carboline was acylated at its 9-position by a chiral acyl chloride, followed by reaction with allyltributyltin and 2,2,2-trichloroethyl chloroformate to afford an 1-allyl-1, 2-dihydrocarboline derivative in a diastereoselective manner. The chiral acyl group at N-9 was readily eliminated by aqueous alkali to give carboxylic acid quantitatively without racemization on C-1 position. The formed 1-allyl-1,2-dihydro-β-carboline was transformed to 1-allyl-1,2,3,4-tetrahydro-β-carboline.