175789-29-4Relevant articles and documents
Chiral N-dienyl-L-pyroglutamic esters in asymmetric hetero-Diels-Alder reactions with acylnitroso dienophiles
Behr, Jean-Bernard,Defoin, Albert,Pires, Joaquim,Streith, Jacques,Macko, Ludwig,Zehnder, Margaretha
, p. 3283 - 3302 (1996)
Asymmetric Diels-Alder reaction of the N-dienyl-L-pyroglutamic esters 1a-h with acyl nitroso dienophiles 4a-h gave diastereoisomeric adducts 6a-n, 7a-n with 12-90% de, depending on solvents and temperature. An interpretation was given. The 'allylic effect' (π(C=C) - σ*(N-C) MO interactions) was found to be effective to account for the conformations of the adducts.