A Diastereoselective and General Route to 5-Amino-5-deoxysugars: Influence of C-3 Substitution on the Addition of Amines to C-5 of Vinyl Sulfone-Modified Hex-5-enofuranosyl Carbohydrates

In the synthesis of vinyl sulfone-modified hex-5-enofuranosides, the E/Z ratios of the products are
influenced by the stereoelectronic property of a group present at the C-3 position. This observation
has been utilized to influence the diastereoselectivity of addition of amines to C-5 of vinyl sulfone-
modified hex-5-enofuranosides, which are efficient Michael acceptors. The stereoelectronic effect
of OMe attached to the β-face of C-3 (gluco derivative) is sufficient to impose diastereoselectivity
overwhelmingly in favor of l-ido-aminosugars when the Michael acceptor is reacted with both
primary and secondary amines. 3-O-Benzylated gluco derivative is also effective in producing l-ido-aminosugars but only in reactions with primary amines. The selectivity is lost when an allo
derivative with OBn at the α-face of C-3 is used. Selected products were desulfonated to establish
this new approach as a general and versatile strategy for accessing 5-amino-5-deoxysugars.