Alternative+project





Phelicia Slade

The formylation of the beta-ionone (I) with methyl formate and NaOMe gives the enol (II), which by reaction with methanol and H2SO4 yields the dimethylacetal (III). The reaction of (III) with methylenetriphenylphosphorane (IV) affords the methylene compound (V), which is treated with formic acid to provide the aldehyde (VI). The condensation of (VI) with isopropylidenemalonic acid dimethyl ester (VII) by means of NaOH gives the polyenic malonic acid (VIII) as a mixture of isomers that is separated by crystallization in ethyl ether to yield the desired all-trans-isomer (IX). Finally, this malonic acid is selectively monodecarboxylated by means of refluxing 2,6-dimethylpyridine to afford the target (E,E,E,Z)-isomer. ﻿Thank You!!!!!