Synthesis of 6-deoxy-N-Cbz-D,L-iminoglycal-derived vinyl epoxides and examination of their regio-and stereoselectivity in nucleophilic addition reactions

The regio-and stereoselectivity of the addition reactions of O-, C-, N-, and S-nucleophiles to 6-deoxy-D,L- iminoallal-and-D,L-iminogalactal-derived epoxides 2a and 2b was examined. Results indicated that the 1,4-/1,2-regioselectivity ratio and the related syn-1,4-/anti-1,2-stereoselectivity is closely and directly dependent on the ability of the nucleophile to coordinate with the oxirane oxygen and the configuration of the epoxide. A formal synthesisof of a 1,6-dideoxy-piperidine azasugar is also described.