The use of sodium chlorite in the direct synthesis of glycidic amides: Enantiopure synthesis of both enantiomers of norbalasubramide

摘要

Recently, the first direct method for preparing 2,3-epoxyamides (glycidic amides) was disclosed. Now in this letter, the enantiopure synthesis of both enantiomers of norbalasubramide featuring this synthetic method is reported. To this end, chiral N-allyltryptamine 12 was prepared and transformed into an inseparable mixture of diastereomeric epoxyamides 13a/13b, which were submitted to intramolecular cyclization with Cu(OTf)_2 to afford a separable mixture of eight-membered ring lactams 14a and 14b. Finally, after removal of the protective group and the chiral auxiliary an enantiopure synthesis of the title compounds was completed.