(3R,5R)-5-Hydroxy-hexahydro-pyridazine-3-carboxylic acid methyl ester

(1R,5R)-7-Oxo-6-oxa-2,3-diaza-bicyclo[3.2.1]octane-2,3-dicarboxylic acid di-tert-butyl ester

(3R,5R)-5-(tert-Butyl-dimethyl-silanyloxy)-tetrahydro-pyridazine-1,3-dicarboxylic acid 3-methyl ester 1-(2-trimethylsilanyl-ethyl) ester