Treatment of 3,4,5-trimethoxycinnamic acid (I) with oxalyl chloride and pyridine produced acid chloride (II). This was then coupled with fumagillol (III), an hydrolyzed product of the fungal metabolite fumagillin, in the presence of NaH in THF to give the title trimethoxycinnamyl ester. Alternatively, fumagillol (III) was coupled with acid anhydride (IV) using DMAP in CH2Cl2.
4-(2-Dimethylaminoethoxy)cinnamic acid (I) was converted to acid chloride (II) upon treatment with thionyl chloride in refluxing benzene. This was then coupled with the sodium alkoxide of fumagillol (III) in THF to furnish the title compound.