Chlorambucil → HCID 46853426, compound

Participants

Reaction Steps

A conformational study of sugar acetylhydrazides by Bendiak indicated that natural hexose and pentose (e.g., D-Glc, D-Gal, D-Xyl, etc.) analogs formed pyranosides, as evidenced by 1H NMR. Similar findings were reported for mono- and oligosaccharide chemoselective ligations with biotinyl, long-chain acyl, peptidyl, and adipyl hydrazides. In contrast, the current chlorambucil study revealed a trend that mirrored that which was observed for the 66-70 subset. Specifically, D-fucoside 72 was formed only as the cyclic compound (67% yield), D-glucuronolactonide 73 and D-xyloside 75 were a mixture of the open and closed conformers (46% and 47%, respectively), and D-threoside 74 adopted the open-chain imine (86%). These results indicate that closure of the glycoside may not only be dependent on the type of sugar but possibly the nature of the aglycon as well. It was also notable that only the β-anomer of the closed-rings was observed while the hydrazyl imines were isolated as mixtures of E- and Z-isomers (FIG. 7).

Provenance & Evidence