A New Synthesis of Dihydropyridin-2-ones from Brassard’s Diene and Imines
摘要:
A new method for the synthesis of dihydropyridin-2-ones from various N-2-nitrobenzenesulfonyl (nosyl) imines and 1,3-diethoxy-1-trimethylsiloxy-1,3-butadiene (Brassard's diene) under weakly-basic conditions is described. This synthesis of dihydropyridin-2-ones involves the initial addition reaction of Brassard's diene to imines to afford the adducts followed by a cyclization reaction that forms the corresponding 4-ethoxy-5,6-dihydro-1H-pyridin-2-ones in moderate to good yields after deprotection of its nosyl group from the adducts.
Hetero Diels–Alder reactions of acyl phosphonates: synthesis of glycosyl type phosphonates
作者:Sidika Polat-Cakir、Ayhan S. Demir
DOI:10.1016/j.tet.2011.02.007
日期:2011.4
We have prepared glycosyl type phosphonates via hetero Diels-Alder (HDA) reactions of acyl phosphonates with electron rich dienes. HDA reactions of acyl phosphonates with Danishefsky's diene required thermal activation to yield the desired dihydropyranones in good yield (70-91%). The reactions with Brassard's diene involved Lewis acid promotion to yield the corresponding lactones, though in moderate yield (33-69%). (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of functionalized 2-alkoxybenzoates, 2-aryloxybenzoates and xanthones based on formal [3+3] cyclocondensations of 3-alkoxy- and 3-aryloxy-1-silyloxy-1,3-butadienes with 3-silyloxy-2-en-1-ones
Functionalized 2-alkoxy- and 2-aryloxybenzoates were prepared by formal [3+3] cyclocondensations of 3-alkoxy- and 3-aryloxy-1-silyloxy-1,3-butadienes with 3-silyloxy-2-en-1-ones. The reaction of 2-aryloxybenzoates with concentrated sulfuric acid resulted in the formation of xanthones. (C) 2009 Elsevier Ltd. All rights reserved.
Synthesis of functionalized arylalkyl and diaryl ethers by [3+3] cyclization of 3-alkoxy- and 3-aryloxy-1-siloxy-1,3-butadienes with 3-(silyloxy)alk-2-en-1-ones
作者:Gerson Mroß、Peter Langer
DOI:10.1016/j.tetlet.2006.09.126
日期:2006.11
Functionalized diaryl ethers were prepared by [3+3] cyclization of 3-aryloxy-1-siloxy-1,3-butadienes with 3-(silyloxy)alk-2-en-1-ones. (c) 2006 Elsevier Ltd. All rights reserved.