Hetero-Diels-Alder Reaction of Enaminecarbaldehydes An Entry to Branched Aminosugars

Article abstract of DOI:10.1016/S0040-4039(00)95013-5

N-acyl-enaminecarbaldehydes 6a - g with an electron accepting group in the α-position react in a hetero-Diels-Alder cycloaddition with enolethers 7a - g to 4-amino-dihydropyrans 8a - g, 9a - g and 10a - g.This reaction represents a convenient entry to branched aminosugars of the garosamine-type.The rate of the cycloaddition depends strongly on the N-acyl group in 6.However, the phtalimide 11 does not react because of deconjugation of the electron accepting function in the α-position.