Two types of insoluble polystyrene resins bearing vinylbenzaldehyde units have been prepared and used with high efficiency as temporary protecting groups in the synthesis of 2,3 disubstituted derivatives of methyl α-D- glucopyranoside.
|Original language||English (US)|
|Number of pages||2|
|Journal||Journal of the Chemical Society, Chemical Communications|
|State||Published - 1975|
Bibliographical noteFunding Information:
Another glucosidic com- ponent of the mixture (9) isolated in 15% yield contained only one benzyl group and could not be crystallized. Similar benzylation of (3)at room temperature with NaH and benzyl chloride in dimethylformamide or KOBu t and benzyl chloride in tetrahydrofuran produced better yields of (8) (30-40%), together with some monobenzylated product (9). The increase in yield observed in the last two benzylations is probably due to the better swelling proper- ties of dimethylformamide and tetrahydrofuran as com-pared to Me,SO. Thus, accessibility of the reactive sites is favoured in the better swelling agents and this results in a more complete benzylation. The fact that a monobenzyl derivative of (3)is obtained in the benzylations may reflect the difficulty of preparing anions on some of the less accessible sites of the resin where ion-ion repulsions may become very important, a fact illustrated by the difficulties experienced3 in the acid-base titrations of resins containing carboxylic acid functional groups. Financial support of the National Research Council of Canada is gratefully acknowledged. (Received, 9th December 1974; Corn. 1481.) 3 JI M. Fr6chet an; C. Schuerch, J. Amer. Chem. SOC.,1971, 93, 492. 4 K. W. Pepper, H. M. Paisley, and M. A. Young, J. Chem. SOC.,1953, 4097. 6D. J. Bell, J. Chem. SOC.,1934, 1177. I? K. Freudenberg and E. Plankenhorn, Bey., 1940, 73, 621.
ASJC Scopus subject areas
- Molecular Medicine