Synthesis of enantiomerically pure 4-alkylsubstituted tryptophan derivatives by a combination of organometallic reactions with enantioselective enzymatic transformations

Article abstract of DOI:10.1016/0040-4039(95)00001-S

The synthesis of enantiomerically pure 4-substituted tryptophans 12 is described. Key steps are i) the introduction of an alkyl substituent into the 4-position of the indole via regioselective lithiation of N-TIPS protected gramine and ii) the enantioselective saponification of the phenyl acetamides of 4-substituted tryptophans by the enzyme penicillin G acylase.