- Synthesis of d8-geranyl diphosphate
-
Multiply labelled d8-geranyl diphosphate (3-methyl-7- 2H3-methyl-[1,1,8,8,8]-2H5-2E,6- octadienyl diphosphate) was synthesised from geraniol in 8 steps. Geraniol was converted to [1,1]-2H2-geraniol by a three step oxidation-reduction sequence in 38% yield. Selective epoxidation of [1,1]- 2H2-geranyl acetate gave 6,7-epoxy-[1,1]- 2H2-geranyl acetate, which, on oxidative cleavage of the epoxide and Wittig elaboration with d6-isopropyl triphenylphosphorane, gave d8-geraniol (14% yield) which was, in turn, converted to the title compound. Copyright
- Comeskey, Daniel J.,Rowan, Daryl D.,Matich, Adam J.
-
-
Read Online
- Total Synthesis of (-)-Sinulariadiolide. A Transannular Approach
-
The constrained tricyclic skeleton of the nor-cembranoid sinulariadiolide (1) with a nine-membered nexus was obtained by a cascade of transannular Michael reaction, carbonate elimination, butenolide formation, and spontaneous oxa-Michael addition of MeOH. The required macrocyclic precursor was prepared by ring-closing alkyne metathesis followed by trans-hydrostannation/carbonylation.
- Meng, Zhanchao,Fürstner, Alois
-
-
Read Online
- Biosyntheses of geranic acid and citronellic acid from monoterpene alcohols by Saccharomyces cerevisiae
-
Geraniol is one of the important aromatic ingredients in alcoholic beverages. Bioconversions of geraniol to other terpenoids and genes involved in the oxidation of geraniol were investigated. Geranic acid and citronellic acid were detected in yeast culture, where geraniol or nerol was added. Addition of citral, a mixture of geranial and neral, resulted in the production of geranic acid and citronellic acid, whereas the addition of citral or citronellal resulted in the production of citronellic acid, suggesting that citronellic acid might be produced through the conversion of citral to citronellal followed by the oxidation of citronellal. Consumption of geraniol and production of geranic acid, citronellic acid, and citronellol were affected in adh1Δ, adh3Δ, adh4Δ, and sfa1Δyeast strains, which possess single deletion of a gene encoding alcohol dehydrogenase. This is the first report of the bioconversion of monoterpene alcohols, geraniol and nerol, to geranic acid and citronellic acid in yeast culture.
- Huang, Shuai,Maeda, Isamu,Ohashi, Yuka
-
p. 1530 - 1535
(2021/08/13)
-
- N-Heterocyclic Carbene/Carboxylic Acid Co-Catalysis Enables Oxidative Esterification of Demanding Aldehydes/Enals, at Low Catalyst Loading
-
We report the discovery that simple carboxylic acids, such as benzoic acid, boost the activity of N-heterocyclic carbene (NHC) catalysts in the oxidative esterification of aldehydes. A simple and efficient protocol for the transformation of a wide range of sterically hindered α- and β-substituted aliphatic aldehydes/enals, catalyzed by a novel and readily accessible N-Mes-/N-2,4,6-trichlorophenyl 1,2,4-triazolium salt, and benzoic acid as co-catalyst, was developed. A whole series of α/β-substituted aliphatic aldehydes/enals hitherto not amenable to NHC-catalyzed esterification could be reacted at typical catalyst loadings of 0.02–1.0 mol %. For benzaldehyde, even 0.005 mol % of NHC catalyst proved sufficient: the lowest value ever achieved in NHC catalysis. Preliminary studies point to carboxylic acid-induced acceleration of acyl transfer from azolium enolate intermediates as the mechanistic basis of the observed effect.
- Berkessel, Albrecht,Biswas, Animesh,Harnying, Wacharee,Sudkaow, Panyapon
-
supporting information
p. 19631 - 19636
(2021/08/09)
-
- Stereocontrolled synthesis and configurational assignment of (R)-all-trans-11,12-dihydro-3-hydroxyretinol
-
The synthesis of (R)-all-trans-11,12-dihydro-3-hydroxyretinol and putative metabolites of the side-chain functional group has been achieved in a stereocontrolled manner via the Suzuki-Hiyama cross-coupling reaction of an enantiopure (hydroxycyclohexenyl)alkenyliodide and non-conjugated pinacolboranedienoate, which allowed the absolute configuration of this natural product to be confirmed.
- Rivas,Alvarez, Rosana,de Lera, Angel R.
-
supporting information
(2019/08/07)
-
- Divergent synthesis of four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid, esters and evaluation for the antifungal activity
-
The four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid 2 were synthesized via the selective direct Sharpless asymmetry dihydroxylation of geraniol as the key step in 35.0%-48.0% overall yields with 91.9%-97.7% ee values for esters 4 and 31.3%-36.4% overall yields with 90.3-97.5% ee values for acids 2 using cis- and trans-geraniol as raw materials. Their structures were characterized by 1H, 13C NMR and HR-ESI-MS data. The in vivo bioassay results showed that the chiral acid (Z, S)-2 was a good lead compound with 80%-100% inhibitory rates against P. cubensis, E. graminis, P. sorghi and C. gloeosporioides at the concentration of 400μg/mL.
- Wang, Weiwei,Zhang, Xiaoteng,Zhao, Yu,Liu, Xinlei,Zhang, Zhenhua,Wang, Mingan
-
supporting information
(2018/03/12)
-
- PLANT OR MICROORGANISM-DERIVED CAROTENOID-OXYGEN COPOLYMER COMPOSITIONS, METHODS OF IDENTIFYING, QUANTIFYING AND PRODUCING SAME AND USES THEREOF
-
The present invention relates to carotenoid-oxygen copolymers, compositions, methods of identifying and quantifying carotenoid-oxygen copolymers in food and related sources, and methods of producing compositions comprising same. In one aspect the method of identifying and quantifying carotenoid-oxygen copolymers comprises an analysis of a low molecular weight marker compound in said sources. In another aspect the present invention provides a method of preparing compositions comprising said carotenoid-oxygen copolymers and/or enhancing levels of said copolymers in food sources in a sufficient and practically useful concentration to have beneficial effects in animals and humans, including beneficial immunological and health effects.
- -
-
-
- Studies on [2?+?3] cycloaddition reaction of nitrile oxides to linear dipolarophiles bearing multiple double bonds
-
Abstract: Site selectivity, regioselectivity, and stereoselectivity of [2?+?3] cycloaddition of benzonitrile oxides to polyunsaturated esters were examined. Site selectivity was correlated with electron charges of unsaturated carbon atoms. Structure of the products has been established by an extensive application of 1H and 13C NMR spectroscopy and electrospray ionization mass spectrometry. Graphical abstract: [Figure not available: see fulltext.]
- Gucma, Miros?aw,Go??biewski, W. Marek,Michalczyk, Alicja Katarzyna
-
p. 1809 - 1818
(2016/09/28)
-
- Catalyzed dehydrogenative coupling of primary alcohols with water, methanol, or amines
-
A working partnership: Metal-ligand cooperativity is responsible for the high activity of the rhodium amido complex 1 in the dehydrogenative coupling of primary alcohols with water, methanol, or amines, including ammonia (see scheme), to give carboxylic acids, methyl carboxylates, or amides, respectively. The catalysis proceeds under mild reaction conditions in the presence of a recyclable hydrogen acceptor A. The multistep mechanism was elucidated by computational methods. (Chemical Equation Presented)
- Zweifel, Theo,Naubron, Jean-Valere,Gruetzmacher, Hansjoerg
-
supporting information; experimental part
p. 559 - 563
(2009/04/14)
-
- Molecular iodine as efficient co-catalyst for facile oxidation of alcohols with hypervalent(III) iodine
-
A simple and mild procedure for the facile oxidation of alcohols to ketones and acids using a catalytic quantity of molecular iodine in combination with (diacetoxyiodo)benzene in acetonitrile is described. Direct oxidative methyl esterification of alcohols is also reported in methanol as solvent. Oxidation of alcohols is induced by iodonium ion generated in situ by the chemical oxidation of molecular iodine with (diacetoxyiodo)benzene. Georg Thieme Verlag Stuttgart.
- Karade,Tiwari,Huple
-
p. 2039 - 2042
(2007/10/03)
-
- ANTIMICROBIAL ACTIVE PREPARATIONS
-
The invention relates to the use of perillic, geranic and citronella acids, the derivatives thereof and citronrllol derivatives in the form of antimicrobial active agents against bacteria, yeast and/or mildew, microorganisms hereafter. Said invention relates, in particular to the use of said antimicrobial active agents for producing cosmetic and pharmaceutical preparations, food product and animal food compounds. Natural monotherpenes and the derivatives of the oxidation products thereof as the antimicrobial active agents are also disclosed.
- -
-
Page/Page column 43
(2008/06/13)
-
- Molecular recognition of α,β-unsaturated carbonyl compounds using aluminum tris(2,6-diphenylphenoxide) (ATPH): Structural and conformational analysis of ATPH complexes and application to the selective vinylogous aldol reaction
-
Various α,β-unsaturated carbonyl compounds were coordinated with aluminum tris(2,6-diphenylphenoxide) (ATPH) to give the corresponding Lewis acid-base complexes in a distinctive coordination fashion (selective coordination). ATPH recognizes carbonyl substrates and subsequently orients itself as it forms a stable complex through selective coordination with the carbonyl oxygen. Selective coordination also confers a conformational preference to each carbonyl compound under the steric and electronic influence of ATPH, which enables the vinylogous aldol reaction of α,β-unsaturated carbonyl compounds to give the corresponding γ-aldol products with different regio- and stereoselectivities.
- Saito, Susumu,Nagahara, Takashi,Shiozawa, Masahito,Nakadai, Masakazu,Yamamoto, Hisashi
-
p. 6200 - 6210
(2007/10/03)
-
- Synthesis and tandem free-radical cyclization of dimethyl (2E,6E)-3-oxo- 6,10-dimethyl-6,10-dodecadiendioate with Mn(III) acetate
-
The synthesis and tandem free-radical cyclization of dimethyl (2E,6E)-3- oxo-6,10-dimethyl-6,10-dodecadiendioate 1 with Mn(OAc)3 are described. The unsaturated β-ketodiester 1 has been prepared from geraniol in six steps and then subjected to the reaction with Mn(OAc)3 giving the bicyclo compounds 10 and 11 in 35% and 45% yields, respectively. The reaction has been carried out under mild conditions and can be very useful method for the synthesis of the desired bicyclo compounds.
- Petrovi?, Zorica D.,Konstantinovi?,Scheffold
-
p. 1364 - 1367
(2007/10/03)
-
- Substrate specificity for the epoxidation of terpenoids and active site topology of house fly cytochrome P450 6A1
-
Heterologous expression in Escherichia coli, purification, and reconstitution of house fly P450 6A1 and NADPH-cytochrome P450 reductase were used to study the metabolism of terpenoids. In addition to the epoxidation of cyclodiene insecticides demonstrated previously [Andersen et al. (1994) Biochemistry 33, 2171-2177], this cytochrome P450 was shown to epoxidize a variety of terpenoids such as farnesyl, geranyl, and neryl methyl esters, juvenile hormones I and III, and farnesal but not farnesol or farnesoic acid. P450 6A1 reconstituted with NADPH-cytochrome P450 reductase and phosphatidylcholine did not metabolize α-pinene, limonene, or the insect growth regulators hydroprene and methoprene. The four geometric isomers of methyl farnesoate were metabolized predominantly to the 10,11-epoxides, but also to the 6,7-epoxides and to the diepoxides. The 10,11-epoxide of methyl (2E,6E)-farnesoate was produced in a 3:1 ratio of the (10S) and (10R) enantiomers. Monoepoxides of methyl farnesoate were metabolized efficiently to the diepoxides. Methyl farnesoate epoxidation was strongly inhibited by a bulky substituted imidazole. The active site topology of P450 6A1 was studied by the reaction of the enzyme with phenyldiazene to form a phenyl-iron complex. Ferricyanide-induced in situ migration of the phenyl group showed formation of the N-phenylprotoporphyrinporphyrin IX adducts in a 17:25:33:24 ratio of the N(B):N(A):N(C):N(D) isomers. These experiments suggest that metabolism of xenobiotics by this P450, constitutively overexpressed in insecticide-resistant strains of the house fly, is not severely limited by stereochemically constrained access to the active site.
- Andersen, John F.,Walding, Jennifer K.,Evans, Philip H.,Bowers, William S.,Feyereisen, Rene
-
p. 156 - 164
(2007/10/03)
-
- Chemical and electrochemical reductions of some allyl type halides catalyzed by vitamin B12
-
Chemical and electrochemical reductions of some attyl type halides catalyzed by vitamin B12 have been studied. Geranyl bromide 1 and methyl (2E, 6E) 8-bromo-3,7-dimethylocta-2,6- dienoate 2 have been used as substrates and subjected to chemical and electrochemical reduction. The formation and distribution of the reaction products of these substrates can be explained by free radical mechanisms, namely by reductive reactions of some functional groups, rearrangements and intermolecular coupling of intermediate radicals.
- Petrovic, Zorica D.,Konstantinovic,Scheffold,Milosavljevic
-
p. 765 - 768
(2007/10/03)
-
- OZONOLYSIS OF ALKENES AND THE REACTIONS OF POLYFUNCTIONAL COMPOUNDS LIII.SYNTHESIS OF THE ESTERS OF 2,3-DIHYDRO DERIVATIVES OF TRI-, DI-, AND MONOPRENOIC ACIDS
-
The esters of the 2,3-dihydro derivatives of geranylgeranic, farnesylic, and geranic acids (di-, sesqui-, and monoterpenoid acids) were synthesized from the products from ozonolysis of 1,5,9-trimethyl-1E,5E,9E-cyclododecatriene.
- Odinokov, V. N.,Kukovinets, O. S.,Sakharova, N. I.,Tolstikov, G. A.
-
-
- Reductive Radical Cyclisations of Bromo Acetals and (Bromomethyl)silyl Ethers of Terpenoid Alcohols
-
The tin hydride promoted and the reductive vitamin B12 catalysed radical cyclisation of mixed 2-bromoacetaldehyde acetals and of (2-bromomethyl)dimethylsilyl ethers of allylic terpenoid alcohols has been investigated: 3-oxadeca-5,9-dien-1-yl radicals undergo 5-'exo' cyclisation to oxolanes (Scheme 4), 3-oxa-2-siladeca-5,9-dien-1-yl radicals sequential 6-'endo' --> 5-'exo' tandem cyclisation to cis-3-oxa-4-silabicyclononanes (Scheme 5), and 3-oxa-2-silatetradeca-5,9,13-trien-1-yl radicals sequential 6-'endo' --> 6-'endo' --> 5-'exo' triple cyclisation to trans-transoid-trans-12-oxa-11-silatricyclo2.6>tridecanes (Scheme 6).
- Lee, Edward R.,Lakomy, Ivo,Bigler, Peter,Scheffold, Rolf
-
p. 146 - 162
(2007/10/02)
-
- Synthesis of Compounds with Juvenile Hormone Activity, XXVII. - Synthesis of Enantiomerically Pure (10R,11S)-(+)-Juvenile Hormone 0
-
The synthesis of (10R,11S)-(+)-juvenile hormone 0 (1) was achieved by employing an improved method for the construction of a trisubstituted double bond.
- Mori, Kenji,Fujiwhara, Mitsuhiko
-
-
- ACTIVATION AND SYNTHETIC APPLICATION OF THIOSTANNANES. PROTECTION OF CARBOXYL GROUPS WITH α-METHYLCINNAMYL ALCOHOL AS A MEANS OF CHEMODIFFERENTIATION AND SELECTIVE ACTIVATION
-
α-Methylcinnamyl (MEC) esters are converted into parent carboxylic acids under mild conditions, various functions being tolerated including acetoxy, siloxy, MEM, and so on.Furthermore, MEC esters are transformed into other esters through CsF-promoted alkylation of intermediary organotin carboxylates.
- Sato, Tsueno,Otera, Junzo,Nozaki, Hitoshi
-
p. 2959 - 2962
(2007/10/02)
-
- THE PHOTOCHEMISTRY OF METHYL GERANATE, A MODEL CHROMOPHORE FOR INSECT JUVENILE HORMONE ANALOGS
-
The irradiation of methyl geranate (3) in ether using 254 nm lamps produces methyl 5-methyl-2-isopropenyl-4-hexenoate (13), 1,6,6-trimethyl-endo-5-carbomethoxybicyclo-hexane (11), methyl 2-isopropenyl-5-methylcyclopentanecarboxylate (12) and methyl (3Z)-3,7-dimethyl-3,6-octadienoate (14).Photolysis run in water or in ether in the presence of base generates two additional dienes: methyl 3-methylene-7-methyl-6-octaenoate (16) and methyl (3E)-3,7-dimethyl-3,6-octadienoate (17).The photolysis of methyl (2E, 6E)-3,7-dimethyl-2,6-nonadienoate (4a) in ether procedures all Z/E isomers, 4a - 4d.
- Freeman, Peter K.,Siggel, Lorenz,Chamberlain, Paul H.,Clapp, Gary E.
-
p. 5051 - 5064
(2007/10/02)
-
- Nuclear Synthons: Mesyltriflone as an Olefin Polyanion Equivalent
-
Mesyltriflone (CF3SO2CH2SO2CH3) is developed as a nuclear synthon reagent capable first of multiple constructions such as alkylations then of Ramberg-Baecklund elimination to a substituted olefin.The alkylations are clean and regiospecific, often amenable to one-pot operation, and in most cases the elimination is smooth.A variety of examples is presented to establish the scope of the method, and the mechanism and stereochemistry are discussed.
- Hendrickson, James B.,Boudreaux, Gerald J.,Palumbo, Paul S.
-
p. 2358 - 2366
(2007/10/02)
-
- PALLADIUM DICHLORIDE CATALYZED COPE REARRANGEMENT OF FUNCTIONALIZED ACYCLIC 1,5-DIENES
-
The cope rearrangement of acyclic 1,5-dienes having an electronwithdrawing group at carbon-3 and an alkyl substituent at carbon-2 is effectively catalyzed by palladium dichloride.This reaction can be employed to achieve clean γ-allylation of vinyl esters and acids.
- Overman, Larry E.,Renaldo, Alfred F.
-
p. 3757 - 3760
(2007/10/02)
-
- OXIDATION OF α,β-UNSATURATED ALDEHYDES
-
A variety of methods for the conversion of α,β-unsaturated aldehydes to the corresponding acids have been explored.The best approach uses sodium chlorite and gives the desired transformation even in systems where steric hindrance and/or sensitive functionality are present.
- Bal, Balkrishna S.,Childers, Wayne E.,Pinnick, Harold W.
-
p. 2091 - 2096
(2007/10/02)
-
- A NOVEL METHOD FOR THE TERPENE SYNTHESIS BY THE RING-OPENING REACTION OF β-METHYL-β-PROPIOLACTONE
-
A new route for the terpene synthesis is investigated, which undergoes via terpene carboxylic acids as key intermediates obtained by the regiospecific ring opening of β-methyl-β-propiolactone with cuprate or with a Grignard reagent in the presence of a copper catalyst.
- Fujisawa, Tamotsu,Sato, Toshio,Kawara, Tatsuo,Noda, Atsunari,Obinata,Toshiyuki
-
p. 2553 - 2554
(2007/10/02)
-
- Inclusion complex compound, process for its production, and method for its use
-
An inclusion complex compound comprising (a) meta-cyclophane and (b) a trans-terpenoid of the formula STR1 wherein n is an integer of 1 to 9; A1 and A2 each represent (1) a hydrogen atom, (2) a halogen atom, (3) an inorganic group containing an oxygen, nitrogen or sulfur atom, (4) an organic group containing 1 to 5 carbon atoms, or (5) an organic group containing an oxygen, nitrogen or sulfur atom and 1 to 5 carbon atoms; and C* is the carbon atom of a carbonyl or methylene group, Included by the meta-cyclophane. This inclusion complex compound can be prepared by contacting the meta-cyclophane with a mixture containing the trans-terpenoid. A trans-terpenoid can be separated from a mixture containing it by utilizing an inclusion complex compound of it with meta-cyclophane.
- -
-
-
- Manufacture of poly-(cis)-isoprenols
-
γ-Alkylation of 2-butynoic acid utilizing lithium 2,2,6,6-tetramethylpiperidide and 1-bromo-3-methyl-2-butene, followed by esterification of the resulting 7-methyloct-6-en-2-ynoic acid and treatment of the ester with lithium dimethyl cuprate, yields methyl (Z)-3,7-dimethylocta-2,6-dienoate. The ester is reduced to (Z)-3,7-dimethylocta-2,6-dien-1-ol, commonly known as nerol, which is useful as perfume agent.
- -
-
-