Co-enzymeQ10 was efficiently synthesised by stereo-and regio-selective prenylation of the protected hydroquinone (2) with isoprene epoxide and solanesyl p-tolyl sulphone in good overall yield.
An improved route to coenzymeQ10 (1) starting from commercially available coenzyme Q1 is described. The key steps in this synthesis are the SeO2-mediated oxidation of the protected isoprenylhydroquinone 3 into the (E)-allyl alcohol 5 without the formation of undesired stereoisomer and the one-pot reductive elimination of the phenylsulfonyl and dibenzyl groups in 7 by using naphthalenyllithium.
A practical, highly stereoselective ten-step synthesis of coenzymeQ10 (1) has been accomplished (overall yield ca. 28%), starting from commercially available 2,3-dimethoxy-5-methylbenzoquinone (Scheme). The introduction of the first side-chain isoprenyl group with (E)-configuration (compound 6) was realized by means of a coupling reaction of the aromatic system 3 with oxirane, followed by Swern oxidation