1: 2,6-dichloro-benzenediazonium With Merrifield resin modified with piperazine in tetrahydrofuran T=0 - 25°C; Solid phase reaction; 2: methanol; 3-hydroxy-1-butene; carbon monoxide With palladium diacetate; trifluoroacetic acid T=40°C; Carbonylation; esterification; P=750.06 Torr; 2 h;