85228-84-8Relevant academic research and scientific papers
Highly S(N)2'-, (E)-, and antiselective alkylation of allylic phosphates. Facile synthesis of coenzyme Q10
Yanagisawa,Nomura,Noritake,Yamamoto
, p. 1130 - 1136 (2007/10/02)
Treatment of secondary allylic chlorides or allylic phosphates in tetrahydrofuran with prenyl Grignard reagent in the presence of CuCN · 2 LiCl gave geraniol or farnesol derivatives with high S(N)2' selectivity. Phosphate leaving groups were highly transstereoselective for the formation of (E,E)-farnesol derivatives. Furthermore, complete anti-S(N)2' selectivity was observed in the alkylation of optically active allylic phosphates. The present method appears to be an excellent carbon-carbon coupling reaction with high regio-, (E)-, and enantioselectivity. Coenzyme Q10 (ubiquinone 10) was efficiently synthesized using this methodology.
Total Synthesis of Linear Polyprenoids. 3. Syntheses of Ubiquinones via Palladium-Catalyzed Oligomerization of Monoterpene Monomers
Eren, Doron,Keinan, Ehud
, p. 4356 - 4362 (2007/10/02)
A general methodology for highly regio- and stereoselective Pd(0)-catalyzed, stepwise allylic coupling of bifunctional monomers was developed, representing a practical approach for total synthesis of naturally occuring polyprenoids.As an example, the total synthesis of the cardiovascular agent ubiquinone 10 (coenzyme Q10), as well as shorter ubiquinones, was carried out via selective coupling of monomers easily derived from geraniol that contain either one or two reacting functional end groups.One of these funcionalities is a latent allylic electrophyle activated by the Pd(0) catalyst and the other is a latent nucleophile activated by an appropriate base.After the desired decaprenyl carbon skeleton of Q10 was achieved, the synthesis was completed by removal of the activating groups: Methyl ester was deleted via a highly efficient demethoxycarbonylation procedure involving 4-aminothiophenol and catalytic amounts of cesium carbonate, and the allylic sulfones were deleted by Pd(0)-catalyzed allylic reduction.Finally, oxidation of the aromatic ring to quinone affords ubiquinone 10.
Quinones. Part 2. General Synthetic Routes to Quinone Derivatives with Modified Polyprenyl Side Chains and the Inhibitory Effects of these Quinones on the Generation of the Slow Reacting Substance of Anaphylaxis (SRS-A)
Terao, Shinji,Shiraishi, Mitsuru,Kato, Kaneyoshi,Ohkawa, Shigenori,Ashida, Yasuko,Maki, Yoshitaka
, p. 2909 - 2920 (2007/10/02)
General synthetic routes to quinone acids (8), quinone amides (9), quinone alcohols (10), and quinone methylketones (11) with polyprenyl side chains, in which allylic alcohols (3) are employed as the key intermediates, are described.The Claisen rearrangements and the Carrol reactions of the allylic alcohols (3) with ethyl orthoacetate and diketen produced the ethyl esters (4) and the methylketones (5), respectively.Quinone products (8), (10), and (11) were recovered by oxidative demethylation of hydroquinone dimethyl ethers (4), (5), and (7) or by acid hydrolysis of hydroquinone bis(methoxymethyl) ethers (4) and (5) followed by ferric chloride oxidation.Amidation of quinone acids (8) led to the formation of quinone amides (9).Inhibitory effects of these quinone derivatives on the generation of the slow reacting substance of anaphylaxis (SRS-A) in the lungs of sensitised guinea pigs are evaluated.
