Synthesis of 5,6-Dihydropyridin-2(1H)-ones, 1,5,6,8,8a-Hexahydroisoquinolin-3(2H)-ones and 4a,5,6,7,8,8a-Hexahydroquinolin-2(1H)-ones by Intramolecular Wittig Reaction

Abstract

A new, universal and diastereospecific method has been developed for the synthesis of 5,6-dihydropyridin-2(1H)-ones, 1,5,6,8,8a-hexahydroisoquinolin-3(2H)-ones and 4a,5,6,7,8,8a-hexahydroquinolin-2(1H)-ones (4) based on the intramolecular Wittig cyclization of the triphenyphosphonium salts 2 derived from the N-(3-oxoalkyl)–chloroacetamides 1.

Intramolecular cyclization of N-(3-oxoalkenyl)phenylacetamides: synthesis of 3-phenyl-2(1H)-pyridones

“…A few years ago we developed the synthesis of 5,6-dihydro-2(1H)-pyridinones and -thiones 6 by intramolecular cyclization of N- (3-oxoalkyl)amides andthioamides 2 [23][24][25][26][27][28][29][30] (Scheme 1). However, only a few examples of cyclization of N-(3-oxoalkenyl)amides 3 to the 2(1H)-pyridinones 7 are known.…”