degrees , NOESY, and HeteroCOSY. Electron donating resonance and electron withdrawing inductive effect of several groups showed marked changes in chemical shifts of nuclei at the seventh positions of O-substituted quinolinols (2-15). Although in N-alkyl, 8-alkoxyquinolinium halides (16-21), ring A rightly showed low frequency chemical shift values.
Chimie des sucres sans groupements protecteurs - I - esterification regioselective de l'hydroxyle anomere du lactose, du maltose et du glucose
作者:Daniel Plusquellec、Fabienne Roulleau、Francoise Bertho、Martine Lefeuvre、Eric Brown
DOI:10.1016/0040-4020(86)80009-6
日期:1986.1
Et3N, afforded high yields of the corresponding reactive amides –, -thioesters – and aryl esters – and –, respectively. The esters -, - and – reacted with excess β-lactose in pyridine, to give the corresponding β-esters, – resulting from esterification of the anomeric hydroxyl of the sugar. The amides , – gave the α-lactosyl esters ,–. The amide and the esters ,, reacted with β-maltose, thus affording