Synthesis of Novel α-C-Glycosylamino Acids and Reverse Regioselectivity in Larock's Heteroannulation for the Synthesis of the Indole Nucleus

Abstract

  An α-C-iodoethynylglucose derivative was coupled with an L-serine-derived zinc-copper reagent to give α-C-glucosylpropargyl glycine, which underwent palladium catalyzed-heteroannulation with o-iodoaniline to give not α-C-glucosyl-tryptophan but α-C-glucosyl-iso-tryptophan. This is the first observation of complete reverse regioselectivity to Larock's proposal.