Stereoselective routes to substituted β-amino carbonyl compounds via heterodiene cycloadditions of an auxiliary-based C2-symmetric ketene acetal
作者:Colin A Ray、Timothy W Wallace、Richard A Ward
DOI:10.1016/s0040-4039(00)00407-x
日期:2000.4
Heterodiene cycloadditions of (S,S)-4,5-bis(o-tolyl)-2-methylene-1,3-dioxolane 1 with a series of substituted β-amido-α,β-unsaturated carbonyl compounds are diastereoselective (dr ≥4:1). The cycloadducts from N-(2-(1-oxoethyl)-3-oxobut-1-enyl)ethanamide 2a can be purified by crystallisation and hydrolysed with acid to generate the corresponding β-amidoacetic esters, the sequence providing an auxiliary-based
(S,S)-4,5-双(邻甲苯基)-2-亚甲基-1,3-二氧戊环1与一系列取代的β-酰胺基-α,β-不饱和羰基化合物的杂二烯环加成是非对映选择性的(dr ≥4:1)。从cycloadducts ñ - (2-(1-氧代乙基)-3-氧代丁-1-烯基)乙酰胺2a中可通过结晶纯化,并用酸,以生成相应的β-amidoacetic酯水解,提供基于辅助立体选择性的序列这类化合物的途径。