Ubiquinone and related compounds. XXXI. Synthesis of urinary metabolites of ubiquinone, phylloquinone, alpha-tocopherol and their related compounds.

Metabolites (XVIIa, b, c) of ubiquinone, phylloquinone and α-tocopherol, and their 2', 3'-dihydro (XXa, b, c), dicarboxy (XVIa, b, XXIIIa, b, c, XXIVa, b and XXVa, b) and 3'-demethyl (XXIa, b) derivatives were synthesized. During the synthetic studies of these compounds, we found that cis-4-acetoxy-1-bromo-2-methyl-2-butene (cis-III) was more reactive to nucleophiles than the corresponding trans isomer. γ-Vinyl-γ-butyrolactone (XII), which was a useful starting material for the synthesis of XXIa, b, was synthesized in one step from 1, 3-butadiene. The 3'-methyl group of XVIIa, b was not essential for the membrane-stabilizing activity in the rat-liver lysosome. Introduction of a carboxyl but not a carboxyl ester group into XVIIa, b resulted in a loss of the stabilizing activity.