Alditols, acetylenic

Addition of phenyl azide to acyclo acetylenic sugar derivatives such as 679 gave a mixture of l-phenyl-4- and 5-(alditol-l-yl)-l,2-3-triazole derivatives (680, 681) (76M110) (Scheme 181). 

Condensation of D-glucose with 1,2-diaminobenzene or its 3-substituted-de-rivatives, then with hydrazine, provided the pyrazoloquinoxalines 107/ Triazolopyrimidopurines such as 108 (and a regioisomer) were obtained by cycloaddition of an acetylene-substituted heterocycle with a 1-azido-l-deoxy-alditol derivatives/ ... 

Ethylidene derivatives of alditols have been made by treatment of an alditol with acetylene in the presence of sulfuric acid and mercuric sulfate 166), Apparently the intermediate vinyl hydroxyethyl ether is formed which then condenses with a second hydroxyl group. 

Cheap methods for the synthesis of various deoxy alditols and ketoses with three to six carbon atoms have been developed, with acetylene as the starting material la). Propargyl alcohol (l-propyn-3-ol) and 3-butyn-2-ol are important intermediates. Formaldehyde or acetaldehyde react with hydrogen atoms adjacent to a triple bond, in the presence of copper acety-lide catalyst. 

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