The stereoselective transformation of the cyclopropyl derivative 2, stereoselectively obtained with the Simmons–Smith reaction of methyl 2,6-di-O-benzyl-alfa-L-threo-hex-4-enopyranoside (1), into gabosines and deoxy-carbahexoses is described. The treatment of 2 with mercuric trifluoroacetate in dry methanol gives the organomercuric chloride 3, which by demercuration with lithium aluminum hydride affords the 4-C-deoxy-4-methyl-1,5-bis-glycoside 4. The acid hydrolysis of 4 produces a mixture of the two diastereoisomeric 2-methyl-cyclohex-2-enones 6 and 7, catalytically reduced to carba-sugars 10 and 11. Structures and stereochemistry of all isolated compounds were determined by 1D and 2D NMR experiments.
|Autori interni:||CATELANI, GIORGIO|
|Autori:||CORSARO A; PISTARA' V; CATELANI G; D'ANDREA F; ADAMO R; CHIACCHIO M.A|
|Titolo:||A new method for the synthesis of carba-sugar enones (gabosines) using a mercury(II)-mediated opening of 4,5-cyclopropanated pyranosides as the key-step|
|Anno del prodotto:||2006|
|Digital Object Identifier (DOI):||10.1016/j.tetlet.2006.07.023|
|Appare nelle tipologie:||1.1 Articolo in rivista|