| abstract |
Described is a process for converting an alcohol to an azide with SN2 inversion using a phosphoryl azide, e.g. diphenylphosphoryl azide (DPPA). Good yields of azide in high enantiomeric excess can be achieved specifically for benzylic alcohols and alpha-hydroxy alkyl esters. The process is carried at preferably room temperature in an inert dry aprotic solvent, e.g. toluene, and in the presence of a proton acceptor, e.g., 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to afford high yields of high enantiomeric purities. |