- A simple synthesis of D-galactono-1,4-lactone and key building blocks for the preparation of galactofuranosides
-
The oxidation of D-galactose by Br2 to yield D-galactono-1,4-lactone was developed and applied to the preparation of key building blocks for the synthesis of galactofuranosides. Three D-galactono-1,4-lactone derivatives protected as acetates, TBDMS ether, or acetonide were directly obtained in two steps on multigram scale with only one purification step. A mild deacetylation methodology afforded pure D-galactono-1,4-lactone and a new reduction of the lactone functionality using K-selectride was also optimized.
- De Talance, Vincent Lemau,Thiery, Emilie,Eppe, Guillaume,Bkassiny, Sandy El,Mortier, Jeremie,Vincent, Stephane P.
-
experimental part
p. 605 - 617
(2012/06/04)
-
- Preparation of acetylated 2,6-anhydrohept(hex)-2-enononitriles (1-cyano-2-hydroxyglycals)
-
The reactions of acetylated 1-bromo-D-glycosyl cyanides with acetate3 and thiolates have been described, and reactions with cyanides are now reported. The mechanism of the formation of the lactones is unclear. Oxidative decyanation of nitriles to give ketones and other carbonyl compounds in the presence of a strong base is well documented. Compounds of the type ArRC(I)CN were converted into ArRC = O with silver oxide in tetrahydrofuran, whereas the corresponding bromides were inert. In these reactions, air is the source of the oxygen. Since the transformations reported here give the lactones in an atmosphere of nitrogen, methyl sulfoxide may be the oxidising agent.
- Somsak,Papp,Batta,Farkas
-
p. 173 - 178
(2007/10/02)
-
