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
Heterodienecycloadditions 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
Organocatalytic enantioselective cycloadditions providing nitrogen-substituted dihydropyran-2-ones were developed in two catalytic systems. The (3R,4R)-product was a versatile intermediate in the synthesis of 1 beta-methylcarbapenem antibiotics.
BAYLES, RICHARD;FLYNN, ANTHONY P.;GALT, RONALD H. B.;KIRBY, SUSAN;TURNER,+, TETRAHEDRON LETT., 29,(1988) N 48, C. 6341-6344
作者:BAYLES, RICHARD、FLYNN, ANTHONY P.、GALT, RONALD H. B.、KIRBY, SUSAN、TURNER,+