Synthesis of C-glycosides via Ramberg-Backlund reaction.

Title: Synthesis of C-glycosides via Ramberg-Backlund reaction.
Identifier: AAI3083722
identifier: 3083722
Creator: Yang, Guangli.
Contributor: Adviser: Richard W. Franck
Date: 2003
Language: English
Publisher: City University of New York.
Subject: Chemistry, Organic
Abstract: A novel methodology has been developed in our laboratory, employing the Ramberg-Backlund rearrangement to synthesize C-glycosides. The Ramberg-Backlund sequence to provide C-glycosides includes three intermediates: thioglycoside, sulfonyl glycoside, and exo-glycal. Thio-glycosides can be easily made using different methods. Sulfone formation was routine with MMPP. The one-pot Ramberg-Backlund reaction of sulfone was done using C2Br2F4, t-BuOH and KOH/Al2O3 under reflux to afford an exo-glycal intermediate. The beta-C-glycosides can be made by hydrogenolysis of exo-glycals using H2 and Pd/C. The alpha-C-glycosides can be made stereoselectively from exo-glycals via intramolecular ionic hydrogenation as the key step. Some of the C-glycerolipids that have been prepared exhibit strikingly similar in vitro antiproliferative effects to those of O-glycoside analogs.
Type: dissertation
Source: PQT Legacy CUNY.xlsx
degree: Ph.D.