112669-93-9

Upstream product

• 112669-91-7 Methyl 4,6-O-benzylidene-2-O-(t-butyldiphenylsilyl)-α-D-ribo-hexopyranosid-3-uloside 
• 21204-67-1 methyl (triphenylphosphoranylidene)acetate 
• 1099-45-2 ethyl (triphenylphosphoranylidene)acetate 
• 104758-89-6 methyl 4,6-O-benzylidene-2-O-pivaloyl-α-D-glucopyranoside 

Downstream Products

• 112669-95-1 Methyl 4,6-O-benzylidene-3-deoxy-3-C-(methoxycarbonylmethylene)-α-D-ribo-hexopyranoside 
• 112669-97-3 Methyl 4,6-O-benzylidene-3-deoxy-3-(ethoxycarbonyl)-2,3-butyrolacto-α-D-allopyranoside 
• 112669-98-4 Methyl 4,6-O-benzylidene-3-deoxy-3-(prop-2-yloxycarbonyl)-2,3-butyrolactone-α-D-allopyranoside 
• 112669-96-2 ((2R,4aR,6S,7R,8aS)-7-Hydroxy-6-methoxy-2-phenyl-hexahydro-pyrano[3,2-d][1,3]dioxin-8-yl)-acetic acid methyl ester 
• 112669-96-2 Methyl 4,6-O-benzylidene-3-deoxy-3-C-(methoxycarbonylmethylene)-α-D-allopyranoside 

Relevant academic research and scientific papers

The 'Off-template' Problem: Towards a General Solution

Wittig reaction of the t-butyldimethylsilylated C-3 ketone methyl 4,6-O-benzylidene-2-O-(t-butyldimethylsilyl)-α-D-ribo-hexopyranosid-3-uloside leads exclusively to C-2 alkenes, providing an efficient synthesis of these potentially useful intermediates.Alternatively, the corresponding t-butyldiphenylsilyl ether, prepared with complete regiospecificity from methyl 4,6-O-benzylidene-α-D-glucopyranoside, gives a C-3 alkene on oxidation and Wittig reaction.Deprotection, hydrogenation and cyclization of this product leads to the cis-fused butyrolactone, methyl 4,6-O-benzylidene-3-deoxy-3-(ethoxycarbonyl)-2,3-butyrolactone-α-D-allopyranoside, which is alkylated stereospecifically to give methyl 4,6-O-benzylidene-3-deoxy-3-(prop-2-yloxycarbonyl)-2,3-butyrolacto-α-D-allopyranoside.This procedure provides a general solution of the 'off-template' problem of carbohydrate-based natural product synthesis.

THE "OFF-TEMPLATE" PROBLEM: SYNTHESIS AND ALKYLATION OF A FUSED-BUTYROLACTONE FROM D-GLUCOSE

The synthesis of a fused-butyrolactone from D-glucose and its stereospecific alkylation in an off-template position is described, together with an unusual silyl protecting group migration.