202271-46-3

Upstream product

• 19488-48-3 methyl O-2,3,6-tri-O-benzyl-α-D-glucopyranoside 
• 111-44-4 3-oxa-1,5-dichloropentane 

Downstream Products

• 202271-48-5 2-{2-[2-(2-{2-[2-((2R,3R,4S,5R,6S)-4,5-Bis-benzyloxy-2-benzyloxymethyl-6-methoxy-tetrahydro-pyran-3-yloxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethoxy}-ethanol 
• 202271-54-3 Methyl-4-O-{2-[ω-acetoxy-penta-(oxyethylen)ethyl]}-2,3,6-tri-O-benzoyl-α-D-glucopyranosid 
• 202271-55-4 Methyl-2,3,6-tri-O-benzoyl-4-O-{2-[ω-hydroxy-penta-(oxyethylen)ethyl]}-α-D-glucopyranosid 
• 202271-53-2 Acetic acid 2-{2-[2-(2-{2-[2-((2R,3R,4S,5R,6S)-4,5-bis-benzyloxy-2-benzyloxymethyl-6-methoxy-tetrahydro-pyran-3-yloxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethoxy}-ethyl ester 
• 202271-50-9 (1R,21S,23R,24S,25R)-24,25-Bis-benzyloxy-23-benzyloxymethyl-2,5,8,11,14,17,20,22-octaoxa-bicyclo[19.2.2]pentacosane 

Relevant academic research and scientific papers

Carbohydrate-based crown ethers containing 1,4-linked D-glucopyranose moieties

The chiral crown ethers 7, 8, 9, and 13 containing a 1,4-bridged α-D-glucopyranose moiety were synthesized from methyl 2,3,6-tri-O-benzyl-α-D-glucopyranoside (1) and methyl 2,3-di-O-allyl-6-O-benzyl-α-D-glucopyranoside (2), respectively, by two subsequent etherification reactions followed by an intramolecular transglycosylation. To build up the hexaethylene glycol chain in 4-position of 1 and 2, bis(2-chloroethyl) ether (generating 3 and 4, respectively) and tetraethylene glycol (yielding 5 and 6, respectively) were used. The cyclizations of 5 and 6 in acetonitrile to the crowns 7 and 8 were catalysed by trimethylsilyl trifluoromethanesulfonate assisted by a 'template' effect of potassium tetrafluoroborate (yield 45-57percent). A high a-stereoselectivity was found for the intramolecular glycosylations even if a benzoylated precursor such as 12 was cyclized (catalyst: BF3 Et2O; yield 25-26percent). Compound 12 was prepared from 5 by exchange of the benzyl groups for benzoyl functions (10-12). Finally, the crown ether 8 was deallylated to generate the crown 9.