Photochemical transformation of a 1,2-dihydropyridin-3-one: an original tandem retro-[4+2]/[2+2] cycloaddition process
作者:David J. Aitken、Angelo Frongia、Xavier Gaucher、Jean Ollivier、Hummera Rafique、Carlo Sambiagio、Francesco Secci
DOI:10.1016/j.tetlet.2013.03.081
日期:2013.5
2-dihydropyridin-3-one furnished trans-1-benzyl-4-phenyl-3-vinylazetidin-2-one, a structural isomer, as the main product. A novel tandem mechanism involving a [4+2] photocycloreversion followed by a Staudinger cycloaddition reaction is proposed, and is supported with the trapping of the purported vinylketene intermediate by other imines. This process predominates in the presence of ethylene, precluding the formation
N-苄基-2-苯基-1,2-二氢吡啶-3-酮的紫外线照射提供了主要结构异构体反式-1-苄基-4-苯基-3-乙烯基氮杂环丁酮-2-酮。提出了一种新的串联机制,该机制涉及[4 + 2]光环还原,然后进行Staudinger环加成反应,并受到其他亚胺捕获所谓的乙烯酮中间体的支持。该过程在乙烯的存在下占优势,排除了分子间[2 + 2]环丁烷加合物的形成。