Utilisation d'ylides du phosphore en chimie des sucres. XX. Synthèse de sucres acétyléniques et réarrangment d'intermédiaires carbénoïdes. Communication préliminaire
作者:Jean M. J. Tronchet、Alberto Gonzalez、Jean-Bernard Zumwald、Françoise Perret
DOI:10.1002/hlca.19740570605
日期:——
chain extension by one carbon unit, are described. In the first procedure, an aldehydo-sugar is treated with dibromomethylenetriphenyl-phosphorane, then with n-butyllithium and finally with water. The second method involves an one-step reaction between an aldehydo-sugar and dimethyl diazomethylphosphonate. The acetylenic sugars obtained are valuable synthetic intermediates for the preparation of heterocyclic
RHODIUM(I)-CATALYZED REGIO- AND STEREOSELECTIVE CHLOROESTERIFICATION OF FURANOSE-DERIVED TERMINAL ALKYNES WITH ETHYL CHLOROFORMATE
作者:Stanislaw F. Wnuk、Carlos A. Valdez、Neida X. Valdez
DOI:10.1081/car-100102544
日期:2001.2.4
Treatment of ribose-, xylose- and homologated ribose-derived terminalalkynes with ethyl chloroformate in the presence of a catalytic amount of RhCl(CO)(PPh3)2 in toluene effected syn chloroalkoxycarbonylation to give doubly functionalized vinylic derivatives.