Izvorni znanstveni članak

Catalytic Hydrogenation of Some 2-Acetamidoaldose Derivatives

N. Pravdić ; Department of Organic Chemistry and Biochemistry, »Ruder Boskovic« Institute, 41000 Zagreb, Croatia, Yugoslavia
B. Židovec ; Department of Organic Chemistry and Biochemistry, »Ruder Boskovic« Institute, 41000 Zagreb, Croatia, Yugoslavia
I. Franjić ; Department of Organic Chemistry and Biochemistry, »Ruder Boskovic« Institute, 41000 Zagreb, Croatia, Yugoslavia
H. G. Fletcher ; National Institute of Arthritis, Metabolism, and Digestive Diseases, National Institutes of Heaith, Public Heaith Service, U. S. Department of Health, Education, and Welfare, Bethesda, Md. 200 .14, U.S. A.

Sažetak

In earlier work, the double bond in aldohexopyranose derivatives
with the grouping C=CNAc2 was shown to be resistant to
catalytic reduction. Further examples of this phenomenon are now
described. Thus, compounds IV, V, and VI were found to be unaltered
by hydrogen in the presence of a palladium catalyst. However,
1,4,6-tri-0-acetyl -2- (N-acetylacetamido) -2,3-dideoxy- a-D-
erythro-hex-2-enopyranose (VII) and its D-threo isomer VIII
undergo allylic hydrogenolysis of the C-1 acetoxy group with
migration of the double bond to the C-1-C-2 position to give IX
and X, respectively. The acetamido group does not inhibit the
reduction of adjacent double bonds; 2-acetamido-1,4,6-tri-0-acetyl-
2,3-dideoxy-a-o-erythro-hex-2-enopyranose (XIII) and 2-acetamido-
4,6-di-0-acetyl -1-0-benzoyl-2,3-dideoxy-a-o-erythro-hex-2-
-enopyranose (XV) are reduced to the same 2-acetamido-4,6-di-O-
-acetyl-1,5-anhydro-2,3-dideoxy-o-arabino (or o-ribo)-hexitol (XIV)
and 2-acetamido-1,4,6-tri-0-acetyl-2,3-dideoxy-~-D-arabino (or o-
ribo)-hexopyranose (XX). Some mechanistic features of these reactions are pointed out. The pattern of selectivity shown in the hydrogenation is discussed and a rationalization of the observed facts is offered.

Ključne riječi

Hrčak ID:

197030

URI

https://hrcak.srce.hr/197030

Datum izdavanja:

30.6.1973.

Posjeta: 469 *