Synthetic studies on coenzyme Q10: Part 31) - An improved C5 + C45 approach to the stereoselective synthesis of coenzyme Q10 via metal-halogen exchange strategy

Article abstract of DOI:10.1002/hlca.200790099

An efficient and stereoselective approach to the synthesis of coenzyme Q₁₀ is described (Scheme). The MeOCH₂-protected p-hydroquinone 4 containing the C₅ (E)-allyl (tert-butyl) dimethylsilyl ether moiety was obtained via a halogen-lithium exchange of the MeOCH₂-proctected 2-bromo-5,6-dimethoxy-3-methylhydroquinone 2 and subsequent addition to (E)-(^tBuMe₂Si)-OCH ₂C(Me)= CHCH₂Br (3). The reductive desulfonylation of compound 8, obtained from 4 via 5-7, was successfully carried out by employing Li/EtNH₂.