2,2'-二硫二吡啶 、
N2′-deacetyl-N2′-(3-mercapto-1-oxopropyl)maytansine 以
乙腈 为溶剂,
以100%的产率得到[(1S,2R,3S,6S,16E,18E,20R,21S)-11-chloro-21-hydroxy-12,20-dimethoxy-2,5,9,16-tetramethyl-8,23-dioxo-4,24-dioxa-9,22-diazatetracyclo[19.3.1.110,14.03,5]hexacosa-10(26),11,13,16,18-pentaen-6-yl] (2S)-2-[methyl[3-(2-pyridyldisulfanyl)propanoyl]amino]propanoate