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Synthesis of Hetaryl Glycosides and Their Glycosyl Donor Properties
Author(s) -
Huchel Ursula,
Schmidt Christoph,
Schmidt Richard R.
Publication year - 1998
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(199807)1998:7<1353::aid-ejoc1353>3.0.co;2-c
Subject(s) - chemistry , anomer , moiety , glycosyl , imide , halide , stereochemistry , disaccharide , fluoride , cyanuric chloride , glycoside , medicinal chemistry , polymer chemistry , organic chemistry , inorganic chemistry
Anomeric O ‐hetarylation of tetra‐ O ‐benzyl‐ and tetra‐ O ‐acetylglucose ( 1a , b ) can be directly performed with electron‐deficient heteroaromatic/heterocyclic systems 2‐14 , which contain imide halide moieties. The reactions were carried out in the presence of a base and led, through an exchange of the halide by the glucopyranosyloxy moiety, to the products 2a–14a , 7b–14b . Predominantly or exclusively β‐products were obtained. Systems bearing more than one imide halide moiety, such as cyanuric fluoride ( 15 ) or 5‐chloro‐2,4,6‐trifluoropyrimidine ( 16 ), can be employed for successive anomeric O ‐hetarylations. Investigation of the glycosyl donor properties of O ‐glucosyl heteroaromatic imidates with 6‐ O‐ and 4‐ O ‐unprotected glucose derivatives 18 and 19 as acceptors and comparison of the results obtained with data for the corresponding β‐trichloroacetimidates 17aβ and 17bβ , reveals that 2,3,5,6‐tetrafluoropyridin‐4‐yl glucopyranosides 14aβ and 14bβ exhibit similar properties. For specific tasks, for instance α‐glucopyranoside formation, 14aβ may even be advantageous.