The Acetolysis of Some Carbohydrate Benzyl Ethers

Abstract

April 5, 1954 ACETOLYSIS OF CARBOHYDRATE BENZYL ETHERS 1757 models of known structure, showed that these three methods were concordant within 10% and were about 90% those of each measured only one sugar, and interference produced ethyl acetate or acetylcholine. In the modified procedure, by equimolar amounts of the others was less than 10%. 0.20 ml. of solution containing 0.3-3 peq. of ester was mixed The Harding and MacLean modification of the ninhydrin with 0.4 ml. of reagent freshly prepared from equal reaction was used*"; this measures amino nitrogen alpha to volumes of 8.0 M hydroxylamine hydrochloride solution carboxyl or carbonyl but not other amines or ammonia. and 1.0 M glycine in 8.5 M sodium hydroxide solution. The hydroxamic acid reaction, under conditions Pre-After 2-3 hr. at room temperature, 2.50 mi. of 1.00 M hyviously described, gave low (3040%) and vari-&-,-,&loric acid and 6.0 ml. of 0.1 M ferric chloride in 0.01 able Color yields with SUgar esters; as modified here (de-M hydrochloric acid were added, and the optical density at creased pH, increased hydroxylamine concentration) it gave molar yields for model sugar esters and a lactonezQ which ref. (28) S. Hestrin, ibid., 180, 249 (1949). *, , 503 Davidson for Preparation of methyl D-galacturonate and chondrosin methyl ester hydrochloride, as well as performance of some of the colorimetry. Other models were D-glucuronolactone, methyl a -Dglucuronate tetraacetate and 8-D-glucose pentaacetate. NEW YORK 32, NEW YORK ( 19 16). (29) We wish to thank Dr. Harold Markowitr for a specimen of amethylgalacturonide methyl ester, used as a standard, and Mr. Eugene The acetolysis of the benzyl ethers of 1,3 : 4,6-di-O-methylene-~-mannitol, 2,4 : 3,5-di-O-methylene-~-iditol, 1,6-anhydro-8-D-glucopyranose and 1,4 : 3,6-dianh~dro-~-mannitol has been studied in mixtures of acetic acid, acetic anhydride and sul-(3) The following abbreviations will be used throughout this paper: PGA, phosphoglyceric acid; DHAP, dihydroxyacetone phosphate; F M P , fructose monophosphate; GMP, glucose monophosphate: SMP, sedoheptulose monophosphate; RDP, ribulose diphosphate; ADP, adenosine diphosphate, ATP, adenosine triphosphate; D P N , diphosphopyridine nucleotide (Coenzyme I), oxidized form; DPN[Hx], diphosphopyridine nucleotide, reduced form.

The Synthesis and Characterization of A Polymer-Supported Cellulose Model

“…In order to distinguish between these two possibilities and verify that the polymer was indeed covalently bound to the 1,5-anhydrocellobiitol, the supported model 1 was exhaustively methylated and the benzyl ether linkage was cleaved by an acid hydrolysis. 32 The hydrolysis also cleaved the disaccharide's glycosidic bond. The products were analyzed by GLC and GC-MS spectroscopy as their alditol acetates.…”

Esterification

“…A dibenzyl ether of n-mannitol is changed to the diacetate by treatment with acetanhydride and a catalytic amount of sulfuric acid (4).…”

“…The catalytic efficiencies of a number of tertiary amines have been compared. 4-Picoline is 6.6 times as effective as pyridine (74).…”