The formal synthesis of kainic acid was carried out in eleven steps. The key cyclization step was accomplished through an intramolecular palladium-catalyzedallylicalkylation of an allylic sulfone. Further functionalization of the resulting pyrrolidone -featured, inter alia, a N-heterocyclic carbene-copper hydride (NHC-CuH)-mediated stereoconvergent conjugate reduction.
practical synthesis of coenzyme Q10 has been developed. The route features an improved Friedel–Crafts allylation of tetramethoxytoluene with a para-chlorobenzenesulfonyl-substituted C5 allylic chloride at 40 °C. Replacement of the methyl ether protecting groups of the para-hydroquinone by methoxymethyl groups at Q1 stage proceeded efficiently, and allowed the facile final oxidation to coenzyme Q10 to
A Large Scale Formal Synthesis of CoQ<sub>10</sub>: Highly Stereoselective Friedel-Crafts Allylation Reaction of Tetramethoxytoluene with (E)-4-Chloro-2-methyl-1-phenylsulfonyl-2-butene in the Presence of Montmorillonite K-10
作者:Sang Who Lee、Hee Bong Lee、Bong Chan Kim、Kadivendi Sadaiah、Kyuwoong Lee、Hyunik Shin
DOI:10.5012/bkcs.2013.34.4.1257
日期:2013.4.20
reported. Use of zinc chloride and bromide resulted in 3.3:1 and 7.4:1 E:Z ratio, respectively (Table 1, entries 1-2) with yields usually less than 20%. Best ratio of 7.6:1 was obtained by the use of boron trifluoride etherate, however with low conversion of ca. 20%. Aluminum chloride also showed marginal conversion of 21% with 3.4:1 E:Z selectivity. Details of the HPLC profiles of these reaction mixtures
Friedel–Crafts allylation of 2-(benzyloxy)-3,4,5-trimethoxytoluene Catalysed by a Metal Trifluoromethanesulfonic Salt: Synthesis of Coenzyme Q10
作者:Yun-Feng Zheng、Jing-Du Lin、Cheng-Ping Li、Jing-Hua Li
DOI:10.3184/030823407x270338
日期:2007.12
In the presence of a catalytic amount of scandium triflate, 2-benzyloxy-3,4,5-trimethoxytoluene reacted with allylic derivatives 4, giving the key intermediate 3 (R = benzyl) which was used for preparing coenzyme Q10, in moderate to high yields.