Unexpected role of O-2 "protecting" groups of glycosyl donors in mediating regioselective glycosidation.
Glycosidation of several vicinal diols reveals that exquisite regioselectivity can be achieved by using 2-O-benzoyl n-pentenyl glycoside donors and/or their cyclic 1,2-ortho ester counterparts. The regioselective preferences for both are the same, although ratios and yields may differ. In stark contrast, glycosidation of the diols with the corresponding 2-O-benzylated donors gives poor, if any, regioselectivity.
Fraser-Reid
Bert
B
Natural Products and Glycotechnology Research Institute Inc. (NPG), 4118 Swarthmore Road, Durham, NC 27706, USA. dglucose@aol.com
Lopez
J Cristobal
JC
Radhakrishnan
K V
KV
Mach
Mateusz
M
Schlueter
Urs
U
Gomez
Ana M
AM
Uriel
Clara
C
D002236:Carbohydrate Conformation; D006027:Glycosides / Q000138:chemical synthesis* / Q000737:chemistry; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D006027:Glycosides