No abstract

Chloroamidation of olefins using a new reagent system (COCl)2-AgNO3-CH3CN was observed. Various glycals with this reagent system produce 2-chloro-1-acetamido sugars in good yields which, in turn, were converted to free amino derivatives and various glycopeptides. The acetamido sugar derivatives and free amines were found to be promising anticancer agents against the U-87 malignant glyoma (a brain tumor) cell line with IC-50=1 nm-22 microM, and they were found to be far less cytotoxic against a normal human embryonic kidney cell line.

No abstract

Diisobutylaluminium hydride (DIBAL-H) mediated reductive removal of benzyl groups was investigated for perbenzylated alpha-, beta- and gamma-cyclodextrins using DIBAL-H in hexane as the reagent. It was found that under the new conditions, the debenzylation can be better controlled to provide sequentially tri- and tetra-debenzylated products in moderate yields and in a regioselective manner. In the case of alpha-cyclodextrin, the removal of the third and fourth benzyl groups took a different path involving the secondary rim, compared to beta- and gamma-cyclodextrins which both gave only 6-O-debenzylated products.