350809-52-8

Upstream product

• 119607-30-6 (+)-2,3,4,6-tetra-O-isobutyryl-α-D-glucopyranosyl bromide 
• 350809-51-7 (+)-(1E)-{(4R,5R,6S)-5-{[(tert-butyl)dimethylsilyl]oxy}-6-hydroxy-4-methoxycyclohex-2-en-1-yliden}acetonitrile 
• 352426-56-3 (-)-(1Z)-{(4R,5R,6S)-5-{[(tert-butyl)dimethylsilyl]oxy}-6-hydroxy-4-methoxycyclohex-2-en-1-yliden}acetonitrile 

Downstream Products

• 352426-54-1 (-)-(1Z)-{(4R,5S,6S)-5-hydroxy-4-methoxy-6-[(2,3,4,6-tetra-O-isobutyryl-β-D-glucopyranosyl)oxy]cyclohex-2-en-1-yliden}acetonitrile 
• 100757-58-2 (-)-(1Z)-[(4R,5S,6S)-6-(β-D-glucopyranosyloxy)-5-hydroxy-4-methoxycyclohex-2-en-1-yliden]acetonitrile 

Relevant academic research and scientific papers

Total synthesis of (-)-bauhinin

The total synthesis of the naturally occurring cyanoglucoside (-)-bauhinin (1) was achieved starting from the optically pure oxatrinorbornenone 2 in 12 steps and 8% overall yield. The aglycone of (-)-bauhinin was easily obtained from the optically pure oxatrinorbornenone derivative 6 by a Wittig-Horner reaction followed by the opening of the oxa bridge. Glycosidation with tetra-O-isobutyryl-D-glucosyl bromide 9 as the reagent in the Koenigs-Knorr reaction afforded glucoside 10 in 58% yield, which, after photoisomerization and deprotection, gave (-)-bauhinin (1).

Selective formation of β-D-glucosides of hindered alcohols

Alternative conditions for the classical glycosidation method of Koenigs-Knorr allowed us to prepare selectively β-D-glucosides of several hindered alcohols in good yields in a weakly acidic to almost neutral medium. To illustrate the versatility of our conditions, we prepared the β-D-glucoside of an acid-sensitive aglycone, a key-intermediate for the total synthesis of a natural cyanoglucoside, bauhinin.