C(6)-Alkylation of 3-Hydroxypiperidine via Reductive and Homolytic Cleavage of N,S-Acetals
作者:Timothy Gallagher、Marc Bartels、Julian Zapico
DOI:10.1055/s-2004-832846
日期:——
N-Carboxymethyl 3-hydroxypiperidine (6) undergoes substitution at C(6) via reductive cleavage of N,S-acetal 8a with lithium naphthalenide (LN) and trapping of the resulting carbanionic intermediate 9 with different electrophiles to give adducts 10. N,S-Acetal 8a also undergoes C-S homolysis and trapping of the resulting radical provides an alternative entry to 2-substituted-5-hydroxypiperidines.
N-Carboxymethyl 3-hydroxypiperidine (6) 通过 N,S-乙缩醛 8a 与萘化锂(LN)的还原裂解在 C(6)处发生取代反应,并通过不同的亲电体捕获生成的碳阴离子中间体 9,从而得到加合物 10。N,S-乙缩醛 8a 还会发生 C-S 均解,由此产生的自由基的捕获为 2-取代-5-羟基哌啶提供了另一种入口。