ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
To demonstrate the neighbouring-group participation of the 2-benzyloxy group in the glycosidation of phenols and of strongly acidic alcohols by the diazirine 1, we examined the glycosidation of 4-nitrophenol, 4-methoxyphenol, (CF3)2CHOH, MeOH, and i-PrOH by the diazirine 11, derived from the 2-deoxypyranose 6. Oxidation of the oximes 7 yielded (E)- and (Z)-8. In solution, (E)-8 isomerised to (Z)-8. Similarly, the (E)-configurated mesylate 9, prepared from 8, underwent acid-catalysed isomerisation to (Z)-9. Treatment of (Z)-9 with NH3, followed by oxidation of the resulting diaziridine 10 with I2, yielded the desired diazirine 11. Glycosidation by 11 of the above mentioned hydroxy compounds yielded the glycosides 12-21. In agreement with the postulated neighbouring-group participation, these glycosidation proceeded without, or with a very low diastereoselectivity, favouring the axial anomers.
Additional Material:
4 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19920750510
