A novel synthesis of 1,2-dehydro-1-aminophosphonates via Beckmann rearrangement. Application to the synthesis of alpha-aminophosphonic acid derivatives

Beckmann rearrangement of oxime mesylates (6a,b and 6d) mediated by TiCl4 in the presence of (EtO)(3)P gave the 1,2-dehydro-1-aminophosphonates (7a,b and 7d) in good yield. The utility of 7a,b was illustrated by a synthesis of a-aminophosphonates (11) and (12).