Preparation of Key Intermediates for the Syntheses of Coenzyme Q 10 and Derivatives by Cross-Metathesis Reactions.

An alternative catalytic strategy for the preparation of benzylmethacrylate esters, key intermediates in the synthesis of coenzyme Q(10) and derivatives, was reported. This strategy avoided undesirable stoichiometric reduction/oxidation processes by utilizing the catalytic formation of allylarenes and then cross-metathesis to selectively form E-benzylmethacrylate esters with good yields (58-64%) and complete E-selectivity. The ester intermediates were reduced to common key benzylallylic alcohols (90-92% yield), which were subsequently used in the formal syntheses of coenzyme Q(10) and one derivative.