Quinic acid derivatives

The vicinal diol 216, prepared in 10 steps from quinic acid, was elaborated into V-alkylated 2-epi-valienamines 217 in variable (16-98%) yield by reaction with Viehe s salt followed by Pd(0)-catalysed coupling with a range of primary e.g. R = H = Et, Bu, Hept, Oct, cyclohexyl, Bn) and secondary amines e.g. R = R = Bu, cyclohexyl, Pr). Carbocyclic influenza neuraminidase inhibitors 219 (n = 3-8) with a cyclic amine side-chain have also been prepared via Pd(0)-catalysed coupling of acetate 218 with the corresponding cyclic amines. The use of pentafunctional quinic acid as a polyoxygenated scaffold for combinatorial synthesis has also been described.  

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Chuda, Y., Suzuki, M., Nagata, T., and Tsushida, T., Contents and cooking loss of three quinic acid derivatives from Garland Chrysanthemum coronarium L.), J. Agric. Food Chem., 46, 1437, 1998. 

The quinic acid derived 2,5,6-trideoxystreptamine analogs 61 was used to prepare 5,6-dideoxyneamine (62) hiosynthetically from Streptomyces fradiae [49]. The crucial intermediate for synthesis of 61 was the hydroxyketone 55, which is readily available from quinic acid. Treatment of 55 with p-toluenesulfonyl chloride in pyridine gave enone 56, which after catalytic hydrogenation generated the saturated ketone 57. Stereoselective reduction of 57, followed by tosylation, furnished deriv-... 

Three a-glycosidase inhibitors of 2,5,6-trideoxystreptamine (compounds 427-429) have been prepared by glycosylation of the quinic acid derived ditosyloxycyclo-hexanol derivative 430, with the corresponding glycal derivatives (e.g., 431 and 432)... 

Anthocyanin (cyanidin) pigmentation can be observed in some cultivars, although its nature has not been fully determined. 3 -Caffeoylquinic is the principal phenolic acid derivative, although 4 - and 5 -caffeoylquinic acids are also present. A concentration of 167 mg caffeic acid per kg has been reported in apricots [19]. The presence of the corresponding p-coumaroyl-and feruloyl quinic acid derivatives has also been reported [16], as have p-coumaroylglucose and feruloyl glucose. 

The main phenolic acid derivative is chlorogenic acid, although 3 -caffeoylquinic and 4 -cafFeoylquinic acids, and p-coumaroyl- and feruloyl-quinic acid derivatives have also been reported [16]. Up to 128mg caffeic acid per kg fresh peaches have been reported [19]. 

Bell peppers, both green and red, contain low amounts of phenolic acid derivatives p-Coumaric (< 4 mg/kg), caffeic (< 10 mg/kg), ferulic (<15 mg/kg), sinapic (<5 mg/kg) and vanillic (10 mg/kg) acids [77]. Caffeoyl glucose, feruloyl glucose and sinapoyl glucose are the main hydroxycinnamic acid derivatives found, while no quinic acid derivatives have been detected [63]. Feruloyl glucose may accumulate up to 11 mg/kg f.w. and sinapoyl glucose up to 5 mg/kg in some red cultivars. 

The known (S.M. Kupchan et. al., J. Org. Chem., 1969, 34, 3898) natural product, crotepoxide A has been isolated from the rhizomes of Kaempferia rotunda and identified as the source of the plants moderate insecticidal activity. It has also been synthesized along with its isomer 93 from a quinic acid derivative as a potential glycosidase inhibitor. (See Vol. 28, p. 239, ref. 123 and 124). 21... 

FIGURE 3 Structure of quinic acid-derived and cinnamic acid-derived fragments. 

Shikimic acid derivatives are formally obtained from quinic acid derivatives by dehydration at the C1-C2 position of the cyclohexane. Cinnamoyl shiki-mic acids occur naturally in several plants such as date or mate [20], In addition, they are formed at elevated temperatures from CGAs through loss of water, for example, in coffee roasting. 

Quinic acid derivatives can be esterified at the carboxylic acid group. It is unclear whether such ester derivatives are actually naturally occurring compounds or whether they are only artifacts of work-up procedures using alcoholic solvents. Nevertheless, we obtained regioisomeric methylesters of caffeoylquinic acid and compared their tandem mass spectra [21]. Again the mass spectra of all four regioisomeric compounds have been different to allow distinguishing between isomers [21]. 

Murray LM, O Brien P, Taylor RJK (2003) Stereoselective Reactions of a (-)-Quinic Acid-Derived Enone Application to the Synthesis of the Core of Scyphostatin. Org Lett 5 1943... 

Scheme 18.71 Rearrangement of iodoso alkene in synthesis of quinic acid derivative.— Scheme 18.72 Propargyl and allenyl sulfenate and sulfoxide f2.31 rearrangements.—...

Phenylpropanoid glycosides and quinic acid derivatives found in Echinacea species. 

In 1998, Armstrong et al. reported a-fluorinated ketone 370a which provided 64% ee for the epoxidation of methyl cumamate [252], Better enantioselectivies are achieved with from (-)-quinic acid derived ketones 404a and 427 for the epoxidation of ethyl cinnamate (86% 404a, 89% ee 427) as reported by Wang et al. in 1999 (Fig. 7.23) [282],... 

Fig. 7.23 (-)-Quinic acid derived ketones and a-fluorinated ketone catalysts...

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