Synthetic Studies on Coenzyme Q₁₀

Abstract

A practical, highly stereoselective ten‐step synthesis of coenzyme Q10 (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 and Wittig olefination. The tosyl (Ts) group in the sulfone 9 was selectively removed with sodium naphthalenide in THF to afford 1.

Catalytic Formation of Hydrogen Peroxide from Coenzyme NADH and Dioxygen with a Water-Soluble Iridium Complex and a Ubiquinone Coenzyme Analogue

“…The progress of the reaction was also monitored by 1 H NMR as shown in Figure . The disappearance of the peak at δ = 6.91 ppm was due to the consumption of NADH, and the new peak appeared at δ = 2.08 ppm that corresponds to a methyl group (−C H 3 ) of Q 0 H 2 at 5 position indicating the stoichiometric conversion from Q 0 to Q 0 H 2 (Figure a,b). , The simultaneous formation of NAD + clearly yields the characteristic peaks at δ ≈ 8.0–9.5 ppm in Figure c. , …”

“…The disappearance of the peak at δ = 6.91 ppm was due to the consumption of NADH, and the new peak appeared at δ = 2.08 ppm that corresponds to a methyl group (−CH 3 ) of Q 0 H 2 at 5 position indicating the stoichiometric conversion from Q 0 to Q 0 H 2 (Figure 2a,b). 35,36 The simultaneous formation of NAD + clearly yields the characteristic peaks at δ ≈ 8.0−9.5 ppm in Figure 2c. 29,37 1-H + was converted to the iridium(III) hydride complex 2 by the reduction with NADH in water at pH 8.8 as reported previously (eq 4).…”

Catalytic Redox Chain Ring Opening of Lactones with Quinones To Synthesize Quinone-Containing Carboxylic Acids

“…Quinone derivatives are an important class of organic compounds that are uniquely oxidative. Some of them are widely distributed in the nature as biological electron transporters; some serve as potent pharmaceuticals and nutritional supplements such as Idebenone, Seratrodast, and Coenzyme Q 10 ; some are powerful oxidants for chemical reactions (for example, 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ)); and recently some of them exhibited new values as battery materials . Great efforts have been devoted to the synthesis of quinone derivatives .…”

Synthetic Studies on Coenzyme Q10. Part 2

“…Colorless oil. 1 7,11,15,19,23,27,31,35,39-decamethyl-5-[(4-methylphenyl)sulfonyl]tetraconta -2,6,10,14,18,22,26,30,34,38-decaenyl}-5,6-dimethoxy-3-methylbenzene (7). To a stirred soln.…”

“…The metalation step turned out to be a bottleneck, hampering the scale-up trials. Thus, the development of an efficient and highly regio-and stereoselective preparation of 1 is still in demand.The SeO 2 -mediated terminal oxidation of an isopropylidene moiety to an allyl alcohol is an important strategy towards the formation of an (E)-allyl alcohol under regio-1 ) For part 1, see [1]. 2 ) Only 65% of 1,4-bis(methoxymethoxy)-2,3-dimethoxy-5-methylbenzene was lithiated by BuLi in the presence of N,N,N',N'-tetramethylethane-1,2-diamine (TMEDA).…”