226211-68-3

Upstream product

• 85716-44-5 methyl 2,3,4-tri-O-benzyl-α-d-xylo-hex-5-enopyranoside 
• 189222-28-4 (1S,2S,3S,4R,5R)-2,3,4-tri-O-benzyl-1-O-methylcyclohexane-1,2,3,4,5-pentol 

Relevant academic research and scientific papers

Epimerisation of carbohydrates and cyclitols, 15. - Non-classical epimerisation of (1S,2S,3S,4R,5R)-1-O-methylcyclohexane-1,2,3,4,5-pentol

Methoxycyclitol 4 was acetalized in a non-classical one-pot procedure with chloral/dicyclohexylcarbodiimide forming the 4-epi derivative 6. The stepwise deprotection of compound 6 is also described. Thus, decarbamoylation to the acetal 7 was achieved by heating 6 with methanolic sodium methoxide, and cleavage of the acid-stable trichloroethylidene moiety was realised in two steps via the corresponding ethylidene acetals 8 and 9; the ethylidene function was removed with aqueous trifluoroacetic acid (compound 10 from 6 via 9). Finally, the carbamoyl derivative 10 was converted into the tetra-O- acetyl product 12 via the tetrol 11.