- A Hantzsch Amido Dihydropyridine as a Transfer Hydrogenation Reagent for α,β-Unsaturated Ketones
-
An improved synthesis of the bis-methylamido Hantzsch dihydropyridine is described. The Hantzsch amide is demonstrated to be an effective transfer hydrogenation reagent using α,β-unsaturated ketones as the test case. Unreacted Hantzsch amide and the bis-methylamidopyridine byproduct are effectively removed by extraction in contrast to the commonly used Hantzsch diethyl ester. Several examples are given with the reaction being more effective for conjugated aromatic substrates than for aliphatics.
- Van Arman, Scott A.,Zimmet, Austin J.,Murray, Ian E.
-
-
Read Online
- Synthesis of raspberry and ginger ketones by nickel boride-catalyzed hydrogenation of 4-arylbut-3-en-2-ones
-
Raspberry and ginger ketones have been synthesized in good yield by the hydrogenation of the corresponding unsaturated precursors 4-(4′- hydroxyphenyl)but-3-en-2-one and 4-(4′-hydroxy-3′-methoxyphenyl)but- 3-en-2-one, respectively, using a freshly prepared suspension of nickel boride in methanol as catalyst.
- Bandarenko, Mikhail,Kovalenko, Vitaly
-
-
Read Online
- Reduction of solid-supported olefins and alkynes
-
(Chemical Equation Presented) The reduction of carbon-carbonmultiple bonds in alkynes and olefins supported on a polystyrene resin has been investigated. Homogeneous catalysis by titanocene reagents is effective for the stereoselective preparation of cis-
- Dickson, David P.,Toh, Christine,Lunda, Menaka,Yermolina, Maria V.,Wardrop, Duncan J.,Landrie, Chad L.
-
-
Read Online
- Heterogeneous Catalytic Synthesis of Zingerone and Dehydrozingerone
-
Abstract: Results of a single-stage heterogeneous catalytic synthesis of zingerone and dehydrozingerone have been described. The prospects of the proposed approach have been shown; the main kinetic laws governing the reaction have been revealed. Optimum conditions for zingerone and dehydrozingerone synthesis providing a yield of the target products of 45.8 and 76.2%, respectively, have been found.
- Chistyakov, A. V.,Chistyakova, P. A.,Tsodikov, M. V.
-
p. 1080 - 1086
(2020/10/02)
-
- GINGEROL DERIVATIVE HAVING INHIBITORY ACTIVITY AGAINST BIOFILM FORMATION AND PHARMACEUTICAL COMPOSITION COMPRISING SAME AS EFFECTIVE INGREDIENT FOR PREVENTING OR TREATING BIOFILM-CAUSED INFECTION SYMPTOM
-
The present invention relates to a gingerol derivative having inhibitory activity against biofilm formation and a pharmaceutical composition for preventing or treating infections caused by biofilms including the gingerol derivative as an active ingredient. The gingerol derivative of the present invention exhibits significantly improved binding affinity for LasR and inhibitory activity against biofilm formation. Therefore, the gingerol derivative of the present invention can act on various membrane surfaces where biofilms tend to form and can effectively inhibit the formation of the corresponding biofilms. In addition, the use of the pharmaceutical composition according to the present invention can fundamentally prevent or treat a variety of infections caused by biofilms due to the presence of the gingerol derivative in the pharmaceutical composition.
- -
-
-
- Chemoselective and metal-free reduction of α,β-unsaturated ketones by: In situ produced benzeneselenol from O -(tert -butyl) Se-phenyl selenocarbonate
-
The carbon-carbon double bond of arylidene acetones and chalcones can be selectively reduced with benzeneselenol generated in situ by reacting O-(tert-butyl) Se-phenyl selenocarbonate with hydrochloric acid in ethanol. This mild, metal-free and experimentally simple reduction procedure displays considerable functional-group compatibility, products are obtained in good to excellent yields, and the use of toxic Se/CO mixture and NaSeH, or the smelly and air-sensitive benzeneselenol, is avoided. This journal is
- Ballarotto, Marco,Siciliano, Carlo,Temperini, Andrea
-
p. 33706 - 33717
(2020/10/22)
-
- Discovery and Characterization of Pure RhlR Antagonists against Pseudomonas aeruginosa Infections
-
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic human pathogen that forms biofilms and produces virulence factors via quorum sensing (QS). Blocking the QS system in P. aeruginosa is an excellent strategy to reduce biofilm formation and the production of virulence factors. RhlR plays an essential role in the QS system of P. aeruginosa. We synthesized 55 analogues based on the chemical structure of 4-gingerol and evaluated their RhlR inhibitory activities using the cell-based reporter strain assay. Comprehensive structure-activity relationship studies identified the alkynyl ketone 30 as the most potent RhlR antagonist. This compound displayed selective RhlR antagonism over LasR and PqsR, strong inhibition of biofilm formation, and reduced production of virulence factors in P. aeruginosa. Furthermore, the survival rate of Tenebrio molitor larvae treated with 30 in vivo greatly improved. Therefore, compound 30, a pure RhlR antagonist, can be utilized for developing QS-modulating molecules in the control of P. aeruginosa infections.
- Nam, SangJin,Ham, So-Young,Kwon, Hongmok,Kim, Han-Shin,Moon, Suhyun,Lee, Jeong-Hoon,Lim, Taehyeong,Son, Sang-Hyun,Park, Hee-Deung,Byun, Youngjoo
-
p. 8388 - 8407
(2020/09/21)
-
- Preparation method of (E)-1-(4-hydroxy-3-methoxyphenyl)-4-ene-3-decalone
-
The invention discloses a preparation method of (E)-1-(4-hydroxy-3-methoxyphenyl)-4-ene-3-decalone and relates to the field of medicinal chemistry. The method comprises the steps as follows: 1) 4-(4-hydroxy-3-methoxyphenyl)-2-butanone is dissolved in a halogenated hydrocarbon solvent, pyrrolidine or piperidine is added at the room temperature, and the mixture reacts for 15-120 min; 2) a halogenated hydrocarbon solution of n-hexaldehyde is added, and the mixture reacts for 2-24 h; 3) an inorganic base solution is added, the mixture reacts for 1-24 h, aftertreatment is performed, and a compoundshown in formula (1) is prepared. Reactions at the room temperature are conducted with inorganic base and other weak bases, and the total yield is 78% or above. The method has mild reaction conditionsand is convenient to operate and suitable for industrial production.
- -
-
Paragraph 0029; 0034; 0036
(2018/07/15)
-
- Structure-Activity Relationships of 6- and 8-Gingerol Analogs as Anti-Biofilm Agents
-
Pseudomonas aeruginosa is a causative agent of chronic infections in immunocompromised patients. Disruption of quorum sensing circuits is an attractive strategy for treating diseases associated with P. aeruginosa infection. In this study, we designed and synthesized a series of gingerol analogs targeting LasR, a master regulator of quorum sensing networks in P. aeruginosa. Structure-activity relationship studies showed that a hydrogen-bonding interaction in the head section, stereochemistry and rotational rigidity in the middle section, and optimal alkyl chain length in the tail section are important factors for the enhancement of LasR-binding affinity and for the inhibition of biofilm formation. The most potent compound 41, an analog of (R)-8-gingerol with restricted rotation, showed stronger LasR-binding affinity and inhibition of biofilm formation than the known LasR antagonist (S)-6-gingerol. This new LasR antagonist can be used as an early lead compound for the development of anti-biofilm agents to treat P. aeruginosa infections.
- Choi, Hyunsuk,Ham, So-Young,Cha, Eunji,Shin, Yujin,Kim, Han-Shin,Bang, Jeong Kyu,Son, Sang-Hyun,Park, Hee-Deung,Byun, Youngjoo
-
p. 9821 - 9837
(2017/12/26)
-
- Selective hydrogenation of conjugated unsaturated ketones containing a hydroxyaryl substituent in the β-position
-
A high selectivity was achieved in the Ni2B-catalyzed hydrogenation of α,β-unsaturated ketones containing a hydroxyaryl (phenolic) substituent in the β-position. The developed hydrogenation procedure was used to synthesize natural compounds of the phenylpropane series and their structural analogs.
- Kovalenko,Pratsko
-
-
- Diazaphospholene Precatalysts for Imine and Conjugate Reductions
-
The first examples of 1,3,2-diazaphospholene-catalyzed imine reduction and conjugate reduction reactions are reported. This approach employs readily synthesized alkoxydiazaphospholene precatalysts that can be handled in open air. Reduction of substrates containing Lewis basic functionality, isolated unsaturation, and protic functional groups was accomplished. The synthetic utility of this approach is demonstrated by the synthesis of the important antiparkinson medicine rasagiline and the natural product zingerone.
- Adams, Matt R.,Tien, Chieh-Hung,Huchenski, Blake S. N.,Ferguson, Michael J.,Speed, Alexander W. H.
-
supporting information
p. 6268 - 6271
(2017/05/19)
-
- Decarboxylative Csp3-Csp3 coupling for benzylation of unstable ketone enolates: Synthesis of: P -(acylethyl)phenols
-
A new decarboxylative Csp3-Csp3 coupling approach for the benzylation of ketone enolates has been developed. A variety of raspberry ketone derivatives were conveniently synthesized in good to excellent yields under mild conditions. A crossover reaction shed light on the mechanism of this tandem reaction.
- Wang, Sasa,Chen, Xinzheng,Ao, Qiaoqiao,Wang, Huifei,Zhai, Hongbin
-
supporting information
p. 9454 - 9457
(2016/07/29)
-
- Feruloylbenzotriazole and weinreb amide as bioinspired building blocks: A reactivity study towards O-, N-, S-, and C-nucleophiles
-
A versatile route for the conversion of ferulic acid into biologically relevant molecules is presented. The compatibility of a number of protection and activation strategies with the 1,2-addition of a variety of O-, N-, S-, and C-nucleophiles to ferulic acid is evaluated. In particular, this report contains the first systematic study of the addition of (hetero)aryllithium reagents to 3-phenylpropenoyl Weinreb amides. The relevance of this "bioinspired" method is illustrated by the synthesis of a number of natural products or analogues, such as zingerone, curcuminoids, and (heteroaryl) chalcones. Feruloylbenzotriazole and Weinreb amide were converted into an array of biologically relevant molecules by addition of O-, N-, S-, and C-nucleophiles. The relevance of this bioinspired approach is illustrated by the synthesis of a number of natural products or analogues, such as zingerone, (heteroaryl) chalcones, and curcuminoids. Copyright
- Roman, Bart I.,Monbaliu, Jean-Christophe,De Coen, Laurens M.,Verhasselt, Sigrid,Schuddinck, Bart,Van Hoeylandt, Evelien,Stevens, Christian V.
-
p. 2594 - 2611
(2014/05/06)
-
- Glycerol/Hypophosphorous acid and PhSeSePh: An efficient and selective system for reactions in the carbon-carbon double bond of (E)-chalcones
-
We describe herein our results for the reaction of benzeneselenol, generated in situ by reaction of diphenyl diselenide with H3PO 2, with various (E)-chalcones using glycerol as solvent. Using our optimized reaction conditions, a range of chemoselective 1,4-reduction products could be obtained in good yields. The glycerol/H3PO2 system can be easily recovered and reused in chemoselective 1,4-reductions for successive cycles without loss of efficiency. Additionally, under 1,4-reducing reaction conditions, the natural product zingerone can be synthesized in good yield. ?2014 Sociedade Brasileira de Qui?mica.
- Mesquita, Katiu?cia D.,Waskow, Bianca,Schumacher, Ricardo F.,Perin, Gelson,Jacob, Raquel G.,Alves, Diego
-
p. 1261 - 1269
(2014/08/05)
-
- Synthesis of quinoline derivatives of tetrahydrocurcumin and zingerone and evaluation of their antioxidant and antibacterial attributes
-
Tetrahydrocurcumin (THC, 1) and zingerone (2) are biologically active molecules originating from the important spices turmeric and ginger, respectively. Novel quinoline derivatives of THC and zingerone have been synthesised by an efficient protocol involving their reaction with substituted 2-aminobenzophenones and 2-aminoacetophenone. Radical-scavenging activities (RSA) of THC, zingerone and their quinoline derivatives were evaluated. The amino-substituted quinoline derivative of THC, 1e, showed antioxidant activity superior to those of 1 and 1a. Derivatives 1b, 1c, 1d and 1f exhibited relatively lower RSA at equimolar concentrations (~50-55 μmol). A similar trend was also seen in zingerone (2) and its derivatives (2a-2e), with 2e displaying the best RSA. Derivatives of THC (1a-1f) showed stronger antimicrobial activity than THC (1) against Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Yersinia enterocolitica. Also, derivatives of zingerone (2b-2e) exhibited lower minimum inhibitory concentrations (MIC) values than zingerone (2) and its derivative, 2a for both Gram-positive and Gram-negative bacteria. The molecules may have potential pharmacological applications.
- Manjunatha,Bettadaiah,Negi,Srinivas
-
p. 650 - 658
(2013/01/15)
-
- Synthesis and neuroprotective effect of E-3,4-dihydroxy styryl aralkyl ketones derivatives against oxidative stress and inflammation
-
E-3,4-Dihydroxy styryl aralkyl ketones as well as their 3,4-diacetylated derivatives as the analogues of neuroprotective agent CAPE were designed and synthesized for improving stability and lipid solubility. The neuroprotective activities of target compounds 10a-g and 11a-g were tested by three models in vitro, including 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity, neuronal protecting effect against damage induced by H2O2 in PC12 cells and nitric oxide suppression effect in BV2 microglial cells. The results demonstrated that compounds 10f and 11f exhibited the most potent neuroprotective effect against oxidative stress and inflammation, which is higher than that of the lead compound CAPE.
- Ning, Xianling,Guo, Ying,Ma, Xiaoyan,Zhu, Renzong,Tian, Chao,Wang, Xiaowei,Ma, Zhizhong,Zhang, Zhili,Liu, Junyi
-
p. 3700 - 3703
(2013/07/25)
-
- Identification of michael acceptor-centric pharmacophores with substituents that yield strong thioredoxin reductase inhibitory character correlated to antiproliferative activity
-
Aims: The role of thioredoxin reductase (TrxR) in tumorigenesis has made it an attractive anticancer target. A systematic approach for development of novel compounds as TrxR inhibitors is currently lacking. Structurally diversified TrxR inhibitors share in common electrophilic propensities for the sulfhydryl groups, among which include the Michael reaction acceptors containing an α,β-unsaturated carbonyl moiety. We aimed to identify features among structurally diversified Michael acceptor-based compounds that would yield a strong TrxR inhibitory character. Results: Structurally dissimilar Michael acceptor-based natural compounds such as isobutylamides, zerumbone, and shogaols (SGs) were found to possess a poor TrxR inhibitory activity, indicating that a sole Michael acceptor moiety was insufficient to produce TrxR inhibition. The 1,7-diphenyl-hept-3-en-5-one pharmacophore in 3-phenyl-3-SG, a novel SG analog that possessed comparable TrxR inhibitory and antiproliferative potencies as 6-SG, was modified to yield 1,5-diphenyl-pent-1-en-3-one (DPPen) and 1,3-diphenyl-pro-1-en-3-one (DPPro, also known as chalcone) pharmacophores. These Michael acceptor-centric pharmacophores, when substituted with the hydroxyl and fluorine groups, gave rise to analogs displaying a TrxR inhibitory character positively correlated to their antiproliferative potencies. Lead analogs 2,2′-diOH-5,5′-diF-DPPen and 2-OH-5-F-DPPro yielded a half-maximal TrxR inhibitory concentration of 9.1 and 10.5 μM, respectively, after 1-h incubation with recombinant rat TrxR, with the C-terminal selenocysteine residue found to be targeted. Innovation: Identification of Michael acceptor-centric pharmacophores among diversified compounds demonstrates that a systematic approach to discover and develop Michael acceptor-based TrxR inhibitors is feasible. Conclusion: A strong TrxR inhibitory character correlated to the antiproliferative potency is attributed to structural features that include an α,β-unsaturated carbonyl moiety centered in a DPPen or DPPro pharmacophore bearing hydroxyl and fluorine substitutions. Antioxid. Redox Signal. 19, 1149-1165. Mary Ann Liebert, Inc.
- Gan, Fei-Fei,Kaminska, Kamila K.,Yang, Hong,Liew, Chin-Yee,Leow, Pay-Chin,So, Choon-Leng,Tu, Lan N.L.,Roy, Amrita,Yap, Chun-Wei,Kang, Tse-Siang,Chui, Wai-Keung,Chew, Eng-Hui
-
p. 1149 - 1165
(2013/10/08)
-
- First bovine serum albumin-promoted synthesis of enones, cinnamic acids and coumarins in ionic liquid: An insight into the role of protein impurities in porcine pancreas lipase for olefinic bond formation
-
During studies on exploiting the catalytic promiscuity of crude porcine pancreas lipase (PPL) in ionic liquid for C=C bond formations, bovine serum albumin (BSA) was found to be competing for these reactions. After a detailed investigation, we establish that these transformations are possible by unspecific protein catalysis rather than catalytic promiscuity of "PPL" - a first insight into the role of protein impurities in crude enzyme. Thus, a novel and highly efficient, environmentally friendly approach involving synergistic catalysis by bovine serum albumin-1-butyl-3- methylimidazolium bromide (BSA-[bmim]Br) has been developed for the synthesis of (E)-α,β-unsaturated compounds including a one-pot cascade synthesis of cinnamic acids and coumarins via aldol, Knoevenagel and Knoevenagel-Doebner condensations.
- Sharma, Nandini,Sharma, Upendra K.,Kumar, Rajesh,Katoch, Nidhi,Kumar, Rakesh,Sinha, Arun K.
-
scheme or table
p. 871 - 878
(2011/06/19)
-
- Protection-, salt-, and metal-free syntheses of [n]-shogaols by use of dimethylammonium dimethyl carbamate (DIMCARB) without protecting groups
-
Shogaols, the pungent principle of ginger, exhibit interesting bioactivities. Practical preparation of shogaols is highly desired. Here we report the protection/deprotection-, salt-, and metalfree synthesis of shogaol in three steps by use of dimethylammonium dimethyl carbamate (DIMCARB), in which DIMCARB smoothly promoted Mannich-type condensation of the ketone donor with the aldehyde acceptor through the iminium cation intermediate. Georg Thieme Verlag Stuttgart.
- Mase, Nobuyuki,Kitagawa, Norihiko,Takabe, Kunihiko
-
scheme or table
p. 93 - 96
(2010/07/16)
-
- Suppression of inducible nitric oxide synthase expression by yakuchinones and their analogues
-
Analogues of yakuchinones were synthesized as inhibitors of nitric oxide production in lipopolysaccharideactivated macrophage cell line, RAW 264.7 cells. We prepared stronger inhibitors than the original natural molecules, yakuchinones A and B reported from Alpinia oxyphylla. From the limited structural activity relation study of analogues, we concluded that the optimal length of linker between two aryl groups and the presence of enone moiety in the linker were identified as essential for the activity. The IC50 value of the most potent structure was 0.92 μM. The active analogues suppressed the expression of inducible nitric oxide synthase protein and mRNA.
- Lee, Hwa Jin,Kim, Ji Sun,Yoon, Joung Wha,Kim, Hee-Doo,Ryu, Jae-Ha
-
p. 377 - 379
(2007/10/03)
-
- Solid-supported green synthesis of substituted hydrocinnamic esters by focused microwave irradiation
-
An efficient chemoselective hydrogenation protocol for substituted cinnamic esters is developed for the synthesis in quantitative yield of corresponding bioactive dihydrocinnamic esters with solid-supported palladium chloride/ammonium formate (cat.) in HCOOH/H2O 1:2 as a hydrogenating agent under focused-microwave irradiation for 10 min.
- Kumar, Vinod,Sharma, Anuj,Sinha, Arun K.
-
p. 483 - 495
(2007/10/03)
-
- A chemoselective hydrogenation of the olefinic bond of α,β- unsaturated carbonyl compounds in aqueous medium under microwave irradiation
-
A microwave-assisted mild and ecofriendly catalytic transfer hydrogenation process was developed to reduce various α,β-unsaturated carbonyl compounds into the corresponding saturated carbonyl compounds in the presence of silica-supported palladium chloride as catalyst and a combination of MeOH/HCOOH/H2O (1:2:3) as hydrogen source within 22-55 minutes in moderate to excellent yields with 100% chemoselectivity.
- Sharma, Anuj,Kumar, Vinod,Sinha, Arun K.
-
p. 354 - 360
(2007/10/03)
-
- Side-chain length is important for shogaols in protecting neuronal cells from β-amyloid insult
-
Ten shogaols were synthesized to evaluate the importance of the side-chain length in protecting cells from βA(1-42) insult using PC12 rat pheochromocytoma and IMR-32 human neuroblastoma cells. The compounds cell protectivity against βA insult was demonstrated using 3-[4,5- dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) reduction assay. The efficacy of cell protection from βA insult by these shogaols was shown to improve as the length of the side chain increase.
- Kim, Darrick S. H. L.,Kim, Jin Yung
-
p. 1287 - 1289
(2007/10/03)
-
- Studies towards the diastereoselective spiroannulation of phenolic derivatives
-
The oxidative spiroannulation of simple phenols bearing a chiral center was carried out. Good yields (61-83%) of spirocompounds were obtained. An increase in diastereomeric ratios from 55/45 to 81/19 was observed as the steric factor surrounding the chiral carbon increased.
- Plourde, Guy L.
-
p. 3597 - 3599
(2007/10/03)
-
- Insect growth inhibition, antifeedant and antifungal activity of compounds isolated/ derived from Zingiber officinale Roscoe (ginger) rhizomes
-
Fresh rhizomes of Zingiber officinale (ginger), when subjected to steam distillation, yielded ginger oil in which curcumene was found to be the major constituent. The thermally labile zingiberene-rich fraction was obtained from its diethyl ether extract. Column chromatography of ginger oleoresin furnished a fraction from which [6]-gingerol was obtained by preparative TLC. Naturally occurring [6]-dehydroshogaol was synthesised following condensation of dehydrozingerone with hexanal, whereas zingerone and 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)butane were obtained by hydrogenation of dehydrozingerone with 10% Pd/C. The structures of the compounds were established by 1H NMR, 13C NMR and mass (EI-MS and ES-MS) spectral analysis. The test compounds exhibited moderate insect growth regulatory (IGR) and antifeedant activity against Spilosoma obliqua, and significant antifungal activity against Rhizoctonia solani. Among the various compounds, [6]-dehydroshogaol exhibited maximum IGR activity (EC50 3.55mg ml-1) while dehydrozingerone imparted maximum antifungal activity (EC50 86.49mg litre-1).
- Agarwal, Manjree,Walia, Suresh,Dhingra, Swaran,Khambay, Bhupinder P. S.
-
p. 289 - 300
(2007/10/03)
-
- PHENYLBUTAN-2-ONE β-D-GLUCOSIDES FROM RASPBERRY FRUIT
-
From a methanolic extract of raspberry fruit, the 4'-O-β-D-glucopyranoside of 4-(4'-hydroxyphenyl)butan-2-one (raspberry ketone) and the 3'-O-β-D-glucopyranoside of 4-(3',4'-dihydroxyphenyl)butan-2-one were isolated by liquid chromatography on XAD-2, Sephadex LH-20 and RP-18 as well as by HPLC on a diol phase.Identifications were carried out by 1H and 13C NMR spectroscopy, using synthetic reference compounds.Assignment of the carbon resonances was made by DEPT and INADEQUATE experiments.The effects of glucosylation on the 13C NMR spectra of phenylbutanone derivatives are discussed.
- Pabst, Anni,Barron, Denis,Adda, Jacques,Schreier, Peter
-
p. 3853 - 3858
(2007/10/02)
-
- AMBERLYST-15 CATALYZED ADDITION OF PHENOLS TO α,β-UNSATURATED KETONES
-
Amberlyst-15 has been used to catalyze regioselective additions of phenols to α,β-unsaturated ketones in yields of 20-90percent.The reaction is superior to the analogous reaction employing concentrated sulfuric acid in affording greater yields and purer products with a minimum of laboratory operations.
- Bunce, Richard A.,Reeves, Henry D.
-
p. 1109 - 1118
(2007/10/02)
-
- Syntheses of the (+/-)--Gingerols (Pungent Principles of Ginger) and Related Compounds through Regioselective Aldol Condensations: Relative Pungency Assays
-
The deprotonation of trimethylsilylzingerone (13) by lithium di-isopropylamide at -78 deg C has been found to be regioselective (92 : 8 in favour of less-substituted enolate): the anion was condensed with alkanals and acyl imidazoles to give convenient syntheses of (+/-)--- and --gingerols (1) and -, -, and -gingerdiones (9).Similary, 3-methoxy-4-trimethylsilyloxybenzylideneacetone (17) gave the (+/-)---dehydrogingerols (8) and -, -, and -dehydrogingerdiones (10).The aldol reaction to -gingerol and methyl -gingerol was also conducted through a vinyloxyborane or through the enol silyl ether (TiCl4 catalysis).Results of organoleptic assays on these compounds are discussed, and the relation between pungency in the gingerols and in capsaicin is commented on.The aldol method was also used to synthesise the natural β-ketols(+/-)-daphneolone (25) and (+/-)-hexahydrocurcumin (4).
- Dennif, Phillip,Macleod, Ian,Whiting, Donald A.
-
-