(S)-2-{(S)-2-[(S)-2-benzyloxycarbonylamino-3-(4-hydroxyphenyl)propionylamino]-4-methylpentanoylamino}-6-iodohexanoic acid methyl ester 在
potassium carbonate 、
caesium carbonate 作用下,
以
乙腈 为溶剂,
以70%的产率得到(7S,10S,13S)-13-benzyloxycarbonylamino-10-isobutyl-9,12-dioxo-2-oxa-8,11-diaza-bicyclo-[13.2.2]nonadeca-1(18),15(19),16-triene-7-carboxylic acid methyl ester