(-)-3-(azidomethyl)-α-(tert-butyloxycarbonylamino)-4-hydroxybenzeneacetic acid 、
7-amino-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid tert-butyl ester 以70%的产率得到7-[[(3-Azidomethyl-4-hydroxyphenyl)-(tert-butyloxycarbonylamino)acetyl]amino]-3-methyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid tert-butyl ester