Syntheses without protection: A three-step synthesis of optically active clavicipitic acid by utilizing biomimetic synthesis of 4-bromotryptophan

Article abstract of DOI:10.1016/S0040-4039(99)01620-2

The optically active clavicipitic acid (4), an ergot alkaloid, was synthesized by a three-step sequence from 4-bromoindole (1). The reaction of 1 with dl-serine (2) in the presence of Ac₂O followed by enzymatic kinetic resolution gave (S)-4-bromotryptophan (3). The Heck reaction of 3 with 1,1-dimethylallylalcohol in aqueous media gave clavicipitic acid in one-pot.