Patent ID: 8835680

Claim:
A process for preparing compound of the Formula I comprises: performing WITTIG reaction under the action of alkali with the substituted tri-phenyl phosphonate (Formula II) and β-formoxyl crotonic acid (Formula III) as raw materials; then performing isomerization by adding palladium compound or rhodium compound to obtain the product compound of Formula I with desired configuration, characterized in that: 1) there is no need to perform hydrolysis after the WITTIG reaction; 2) there is no need to separate the products of WITTIG reaction, but performing isomerization directly; the WITTIG reaction and the isomerization are conducted continuously in one container; 3) adjusting the pH of reaction liquid to 5-10 by adding acid before the isomerization; in Formula I, the carbon-carbon double bonds on site 2-3, site 4-5 and site 6-7 have cis or trans configuration; in Formula II and Formula III, the carbon-carbon double bonds on site 2-3 have cis or trans configuration; in Formula I and Formula II, A is substituted unsaturated hexatomic carbocyclic group; X is selected from Cl, Br or HSO 4 .