| abstract |
A process for the preparation of a compound of formula (I),n ncomprising: na) the reaction of a compound of formula (II)n nwith hydrazine to obtain a compound of formula (III),n nb) the conversion of a compound of formula (III) by rearrangement via formation of nitrene/isocyanate, in a solvent of formula R 1 -OH, wherein R 1 is as herein defined, to obtain a compound of formula (IV);n nc) the enantiomeric enrichment of a compound of formula (IV) to obtain the enantiomer (S) of a compound of formula (V)n nd) the hydrolysis of a compound of formula (V). |