Phenylsulfonyl Ene−Allenes as Efficient Precursors to Bicyclic Systems via Intramolecular [2 + 2]-Cycloaddition Reactions
作者:Albert Padwa、Helmut Lipka、Scott H. Watterson、S. Shaun Murphree
DOI:10.1021/jo0345796
日期:2003.8.1
stereospecificity involves initial diradical formation, followed by a rapid ring closure to the more stable cis-fused ring system. The tether may be equipped with heteroatoms, allowing for the formation of fused heterocycles (e.g., 61), and the cycloaddition can be facilitated by the introduction of sterically bulky groups and/or by conformational rigidity to the tether. Other modes of cyclization were observed