Strukturelle Abwandlungen an partiell silylierten Kohlenhydraten mittels Triphenylphosphan-Azodicarbons�ureester, 5. Mitt.: Transformationen an Glykonolactonen

Protecting group migrations in carbohydrate chemistry

Protecting groups are valuable in chemo- and regioselective synthetic manipulations. In particular, they are indispensable in carbohydrate chemistry. Although a wide array of protecting groups are available at the disposal of carbohydrate chemists, their stability and orthogonality make the choice of protecting groups challenging. Another important factor is the migratory aptitude of different protecting groups used in carbohydrate chemistry. Migration of commonly used groups like silyl, acetal and acyl groups under various reaction conditions are discussed. Synthetic application of predicted migrations, alternate protecting groups to avoid migration and conditions favoring and disfavoring migrations are discussed in this review.

Effect on human liver glycosidases and short syntheses of 1 alpha,2 alpha,6 alpha,7 alpha,7a beta-1,2,6,7-tetrahydroxypyrrolizidine from D-glycero-D-gulo-heptono-1,4-lactone

The synthesis of 1 alpha,2 alpha,6 alpha,7 alpha,7a beta-1,2,6,7-tetrahydroxypyrrolizidine (1) from D-glycero-D-gulo-heptono-1,4-lactone (6) by two different routes is reported. The effects of 1 on the inhibition of 15 human liver glycosidases are described.