Alkyl benzyl ethers bearing a carbonyl moiety in the alkyl chain (1) cyclize effectively, without the Wittig rearrangement or protophilic decomposition, to give hydroxytetrahydrofurans (trans-2) on treatment with ButOK in DMSO at room temperature, whereas LDA–THF induces the cyclization of 1 to afford predominantly the stereoisomer cis-2.
烷基链中带有羰基的烷基苄基醚(1)在室温下与
DMSO中的ButOK反应时,无需进行Wittig重排或亲核分解即可有效环化,生成羟基
四氢呋喃(反式-2),而
LDA-THF则诱导1环化,主要生成立体异构体顺式-2。