
TY  - JOUR
A1  - Hajko, J 
A1  - Szabovik, G 
A1  - Kerekgyarto, J 
A1  - Kajtar, M 
A1  - Liptak, A 
T1  - Hydrogenolysis of the 4,6-O-Ketals of Glucopyranosides. Configuration-Dependent High Regio- and Stereo-Selectivity of the Diastereoisomeric Acetophenone Derivatives
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1996
VL  - 49
IS  - 3
SP  - 357
EP  - 363
KW  - 
UR  - https://doi.org/10.1071/CH9960357 
N2  - Hydrogenolysis (reductive cleavage) of the (R) isomers of the acetophenone 4,6-O-derivatives of glucopyranosides with LiAlH4/AlCl3 gives the 4-O-(1'-phenylethyl) ethers with (R) configuration; the corresponding (S) isomers produce the respective (R) 6-O-(1'-phenylethyl ) ethers are produced. The hydrogenolysis of other 4,6-O-ketals affords O 4 ether derivatives; the two diastereoisomeric 4,6-O-s-butylidene derivatives (cyclic ketals ) give O 4-ethers with the opposite absolute configuration. The stereoselectivity of these reactions is explained by the development of a four-centre transition state. The absolute configuration of the ethers has been determined by means of circular dichroism measurements. 
ER  -

