STUDIES IN SESQUITERPENES. PART I. SYNTHESIS OF THE TRIMETHYL ESTER OF C3H15(CO2H)3-ACID OBTAINED FROM DIHYDROZINGIBERENE

Condensation of diethyl α-methyl-α(bromoacetyl)-glutarate with malonic ester, followed by hydrolysis and esterification, furnishes (V) which on treatment with zinc and bromoacetic ester gives the lactone (VI). On reduction of the above lactone, followed by esterification, (X), the trimethyl ester of C₈H₁₅ (CO₂H)₃ acid, is obtained.