Neighbouring group effects in a Pummerer-type rearrangement: A facile entry into 3,1-benzoxathiins
作者:Ian D. Kersey、Colin W.G. Fishwick、John B.C. Findlay、Peter Ward
DOI:10.1016/0040-4020(95)00315-y
日期:1995.6
Arylmethyl sulphoxides treated with trialkylsilyl halide and base undergo a Pummerer-type rearrangement to give α-siloxy and α-chlorosulphides. However, the presence of an ortho hydroxymethyl group results in the exclusive and efficient formation of the α-chlorosulphides, presumably mediated via an intramolecular attack to yield an alkoxysulphonium salt. These 2-(hydroxymethyl)aryl chloromethylsulphides
用三烷基甲硅烷基卤化物和碱处理的芳基甲基亚砜经过Pummerer型重排,得到α-甲硅烷氧基和α-氯代硫化物。然而,邻羟甲基的存在导致α-氯硫化物的排他且有效的形成,大概是通过分子内攻击来介导以产生烷氧基砜盐。然后,可以通过分子内环化将这些2-(羟甲基)芳基氯甲基硫化物转化为相应的3,1-苯并黄皮素。初步研究了这些3,1-苯并噻嗪类化合物的化学性质,发现在一种情况下,发生了一种新型的碱诱导的环收缩,产生了苯并噻吩。