exocyclic enol esters followed by alkali ring-opening of the three-membered ring was used for the diastereoselective preparation of 5-C-methylated d-mannose, d-galactose, l-gulose, and l-altrose. Extensive NMR studies demonstrated an increase of furanose form by 5-C-methylation in almost all cases.
将环外烯醇酯的C5 / C6-螺
环丙烷化,然后三元环的碱开环用于5- C-甲基化的d-
甘露糖,d-半
乳糖,1- gulose和1- altrose的非对映选择性制备。广泛的NMR研究表明,几乎在所有情况下,5- C-甲基化都会使
呋喃糖形式增加。