214771-14-9

Upstream product

• 6386-24-9 2,3,4,6-tetra-O-benzyl-D-galactopyranose 
• 82598-84-3 2,3,4,6-tetra-O-benzyl-D-galactonolactone 
• 402849-67-6 ethyl 2-deoxy-4,5,6,8-tetra-O-benzyl-α-D-galacto-3,7-pyranoso-3-octulosonate 
• 1099-45-2 ethyl (triphenylphosphoranylidene)acetate 

Downstream Products

• 82598-85-4 ethyl (2,3,4,6-tetra-O-benzyl-β-D-galactopyranosyl)ethanoate 
• 236739-66-5 ethyl acetoxy(1-acetoxy-2,3,4,6-tetra-O-benzyl-D-galactopyranosyl)ethanoate 

Relevant academic research and scientific papers

Stereocontrolled synthesis of β-C-glycosides and amino β-C-glycosides by Wittig olefination of perbenzylated glyconolactones derivatives

Wittig olefination of perbenzylated glyconolactones afforded stereoselectively the Z-C-glycosylidenes which were transformed to the corresponding β-C-glycosides and amino β-C-glycosides by hydrogenation followed by acetylation.

Stereochemistry in the synthesis and reaction of exo-glycals.

Two general methods are explored for the stereoselective synthesis of exo-glycals. One method utilizes a nucleophilic addition of fully protected sugar lactones of gluco-, galacto-, and manno-types, followed by the subsequent dehydration, to give the desired exo-glycals with (Z)-configuration. The other method proceeds with selenylation of C-glycosides in a stereoselective manner. The subsequent selenoxide elimination also provides (Z)-exo-glycals. The prepared exo-glycal conjugated esters of either gluco- or manno-type react with allyl alcohol to give exclusively alpha-anomers.

Alkylidenation of sugar lactones and further transformation to C-glycosides

The Wittig reaction of (carbethoxymethylene)triphenylphosphorane with perbenzylated sugar δ-lactones and their 2-acetamido-2-deoxy derivatives is described. It is shown that this olefination occurred readily with the galacto and gluco derivatives, leading stereoselectively to Z-C-glycosylidenes in good yields. However, the same reaction with the perbenzylated 2-deoxy-D-arabino-hexono-1,5-lactone and the mannonolactones worked poorly. Reduction over Pd/C followed by acetylation of the obtained C-glycosylidenes led stereoselectively to peracetylated β-C-glycosides and amino β-C-glycosides. The olefin function could also be reduced selectively by Raney nickel or NiCl2/NaBH4, affording the perbenzylated C-glycosides and amino β-C-glycosides. Other transformation of the enol ether function is also reported.