Towards Enantioselective Synthesis Of Tryptophan-Derived Alkaloids

Tryptamine was subjected to a series of reactions with derivatives of L-Ala, L-Val that ended with final diketopiperazines 9 and 10, having (R) configuration on the newly created, via 1,4-chirality transfer, stereogenic center. On the other hand, when L-Pro was used the opposite chirality sense was formed at this position.