Stereoselective routes to substituted β-amino carbonyl compounds via heterodiene cycloadditions of an auxiliary-based C2-symmetric ketene acetal

Article abstract of DOI:10.1016/S0040-4039(00)00407-X

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 stereoselective route to such compounds. (C) 2000 Elsevier Science Ltd.