Dérivés C‐glycosyliques. VII. Synthèse et réactions de nitrones dérivées de sucres. Communication préliminaire

Abstract

Abstract The syntheses of three types of sugar nitrones (aldonitrone, ketonitrone and α‐β unsaturated aldonitrone) are described. On 1,3‐dipolar cycloaddition with phenylacetylene, the aldonitrone gave two Δ 4 ‐isoxazolines epimeric at the new asymetric carbon, while the same reaction on the ketonitrone led to a spiro ‐Δ 4 ‐isoxazoline. The reaction of these nitrones with carbon nucleophiles like phenylethynylmagnesium bromide constitutes a novel chain‐extension reaction in carbohydrate chemistry.