1: methyl (2E)-3-phenyl-2-propenyl carbonate With tris(dibenzylideneacetone)dipalladium(0) chloroform complex; tris-(o-tolyl)phosphine in tetrahydrofuran T=20°C; 0.25 h; 2: 4-Bromo-crotonoic acid ethyl ester With indium in tetrahydrofuran T=65°C; 24 h;

N,N,N',N',N'',N''-hexamethylphosphoric triamide; lithium diisopropyl amide 1) THF, -78 deg C, 15 min, 2) THF, 20 min; Yield given. Multistep reaction;