作者:Albert Padwa、Stephen P. Carter、Ugo Chiacchio、Donald N. Kline、John Perumattam
DOI:10.1039/p19880002639
日期:——
and γ-substituted products. With methyl iodide as the electrophile, only the α-methylated product was isolated. In contrast, reaction of the 5-exo-methylene-4-phenylsulphonylisoxazolidine with allyl bromide afforded the γ-allylated product. Formation of this was shown to be via direct γ-attack, rather than by α-attack, followed by a 3,3-sigmatropic rearrangement. Further studies show that the product
将硝酮的1,3-双极环加成至苯基磺酰基烯丙基可产生高产率且具有完全的区域特异性的5-亚甲基异恶唑烷。这些在用碱处理以及随后与亲电试剂反应时得到α-和γ-取代的产物。用甲基碘作为亲电子试剂,仅分离出α-甲基化产物。相反,5-外-亚甲基-4-苯基磺酰基异恶唑烷与烯丙基溴的反应提供了γ-烯丙基化的产物。它的形成是通过直接的γ攻击而不是通过α攻击,然后是3,3σ重排而形成的。进一步的研究表明,产物比率是由热力学和空间因素之间的敏感相互作用控制的,并且非常取决于所用亲电试剂的性质。