Ring closing metathesis of unsaturated amides as a route to short and medium-sized unsaturated lactams and to ethylenic pseudopeptides

摘要

Five- to eight-membered unsaturated lactams have been obtained through ring-closing metathesis of unsaturated amides of various chain lengths and substitution patterns. The obtention of nine-membered unsaturated lactams by the same procedure met only with limited success. Also described in this Letter is the obtention of the Z-ethylenic pseudopeptidic analog of L-Phe-L-Phe through hydrolytic ring opening of (3R, 6S)-3,6-dibenzyl-3,6-dihydro-2-pyridone obtained by RCM. [References: 19]