The structure of β-heteroaryl-α,β-dehydro-α-amino acid derivatives,intermediates in the synthesis of fused pyran-2-ones. Substituted methyl (Z)-2-benzoylamino-3-(5-oxopyrazolinyl-4)propenoates

It was shown by some chemical transformations that β-heteroaryl-α,β-dehydro-α-amino acid derivatives 3 and 7 , obtained from pyrazolone derivatives 1 or 6 and 2 , exist in Z-forms. The structure of 7 was confirmed by X-ray analysis.