in a stereoselective and quantitative reaction. Condensation of 5-azido-5-deoxy-d-glucurono-3,6-lactone (1b) withl-cysteine methyl ester followed by the reduction of the azido group yields the rigid β-turn mimetic2d in a minimum of reaction steps.
Regioselective Conversion of the Secondary Hydroxyl Groups ofD-Glucuronic Acid without the Requirement ofO-Protecting Groups
作者:Károly Ágoston、Armin Geyer
DOI:10.1002/chem.200500515
日期:2005.10.21
Trifluoromethanesulfonic acid anhydride (triflic acid anhydride) transforms the bicyclic thiazolidinlactam 1 a into the crystalline elimination product 2, in which all four secondaryhydroxylgroups of 1 a are differently functionalized. Compound 2 can then add nucleophiles with high chemo- and stereoselectivity. Altogether, the four secondaryhydroxylgroups of D-glucuronic acid are selectively transformed