Synthetic Studies on Coenzyme Q₁₀. Part 3

Abstract

An efficient and stereoselective approach to the synthesis of coenzyme Q 10 is described (Scheme). The MeOCH 2 -protected p-hydroquinone 4 containing the C 5 (E)-allyl (tert-butyl)dimethylsilyl ether moiety was obtained via a halogen -lithium exchange of the MeOCH 2 -proctected 2-bromo-5,6dimethoxy-3-methylhydroquinone 2 and subsequent addition to (E)-( t BuMe 2 Si)-OCH 2 C(Me) ¼ CHCH 2 Br (3). The reductive desulfonylation of compound 8, obtained from 4 via 5 -7, was successfully carried out by employing Li/EtNH 2 .