Stereochemically controlled syntheses of indole-substituted dihydrofuran-2-ones and a pyrrolidin-2-one

In order to obtain constrained analogues of tryptophane, five-membered lactams and lactones bearing 4-indolyl and 3-carboxylic groups were prepared in a completely diastereoselective manner, resulting in a trans relationship. Furthermore, the use of chiral precursors in the synthesis yielded enantiomerically pure compounds with three contiguous chiral centres.