名称:
Cycloaddition reactions of λ-amino α,β-didehydro amino acid esters: a test case for the principle of 1,3-allylic strain
摘要:
N,N-Dibenzylainino aldehydes, readily accessible from amino acids, can be converted into gamma-N,N-dibenzylamino alpha,beta-didehydro amino acid esters without racemization; these undergo stereoselective Diels-Alder reactions and 1,3-dipolar cycloaddition with diazomethane, the sense of diastereoselectivity being opposite to that predicted by the conventional principle of 1,3-allylic strain.