21090-68-6Relevant academic research and scientific papers
A Synthesis of (-)-(R)- and (+)-(S)-Lavandulol, (+)-Lavandulyl 2-methylbutanoate, and (+)-lavandulyl senecioate through orthoester johnson-claisen rearrangement
Fernandes, Rodney A.,Chowdhury, Asim K.
, p. 5165 - 5170 (2013)
An efficient synthesis of (-)-(R)- and (+)-(S)-lavandulol, (+)-lavandulyl 2-methylbutanoate and (+)-lavandulyl senecioate is presented in this paper. The synthetic strategy features a chiral-pool approach to an allyl alcohol intermediate, and an orthoester Johnson-Claisen rearrangement as the key step. An efficient synthesis of (-)-(R)- and (+)-(S)-lavandulol, (+)-lavandulyl 2-methylbutanoate and (+)-lavandulyl senecioate is presented. The synthetic strategy features a chiral-pool approach to an allyl alcohol intermediate, and an orthoester Johnson-Claisen rearrangement as the key step. Copyright
Enantio- and diastereoselective protonation of photodienols: Total synthesis of (R)-(-)-lavandulol
Piva
, p. 7879 - 7883 (1995)
The total synthesis of (R)-(-)-lavandulol 1 has been achieved by asymmetric protonation of photodienols obtained from the irradiation of prochiral α,β-unsaturated esters. The photodeconjugation of ethyl 5-methyl-2-(1'-methylethylidene)-4-hexenoate (3a), carried out in the presence of catalytic amounts of a β-amino alcohol prepared from (±)-camphor, gives the β,γ-unsaturated isomer 2a in good yields but with moderate enantioselectivities (40% ee). In contrast, irradiation of the corresponding ester 3b, bearing the 1,2:5,6-di-O-isopropylidene-D-glucose group as a chiral alkoxy moiety, affords the deconjugated product 2b in high de (> 95%). Simple reduction of the ester function with LiAlH4 gives (R)-(-)-lavandulol (1) without loss of optical purity.
Asymmetric α-alkylation of α,β-unsaturated esters. Application to the synthesis of (R)-lavandulol, (R)-sesquilavandulol and related trifluoromethyl compounds
Faure,Piva
, p. 1414 - 1416 (1998)
Diastereoselective α-alkylation/deconjugation of esters of diacetone D-glucose has been performed and applied to the syntheses of (R)-lavandulol, (R)-sesquilavandulol with de up to 74%. The same reaction performed with trifluoromethyl derivatives was also
Chrysanthemyl diphosphate synthase operates in planta as a bifunctional enzyme with chrysanthemol synthase activity
Yang, Ting,Gao, Liping,Hu, Hao,Stoopen, Geert,Wang, Caiyun,Jongsma, Maarten A.
, p. 36325 - 36335 (2014)
Chrysanthemyl diphosphate synthase (CDS) is the first path-way-specific enzyme in the biosynthesis of pyrethrins, the most widely used plant-derived pesticide. CDS catalyzes c1′-2-3 cyclopropanation reactions of two molecules of dimethylallyl diphosphate (DMAPP) to yield chrysanthemyl diphosphate (CPP). Three proteins are known to catalyze this cyclopropanation reaction of terpene precursors. Two of them, phytoene and squalene synthase, are bifunctional enzymes with both prenyltransferase and terpene synthase activity. CDS, the other member, has been reported to perform only the prenyltransferase step. Here we show that the NDXXD catalytic motif of CDS, under the lower substrate conditions prevalent in plants, also catalyzes the next step, converting CPP into chrysanthemol by hydrolyzing the diphosphate moiety. The enzymatic hydrolysis reaction followed conventional Michaelis-Menten kinetics, with a Km value for CPP of 196 μM. For the chrysanthemol synthase activity, DMAPP competed with CPP as substrate. The DMAPP concentration required for half-maximal activity to produce chrysanthemol was ～100 μM, and significant substrate inhibition was observed at elevated DMAPP concentrations. The N-terminal peptide of CDS was identified as a plastid-targeting peptide. Transgenic tobacco plants overexpressing CDS emitted chrysanthemol at a rate of 0.12-0.16 μg h-1 g-1 fresh weight. We propose that CDS should be renamed a chrysanthemol synthase utilizing DMAPP as substrate.
PROCESSES FOR PREPARING 2-ISOPROPENYL-5-METHYL-4-HEXENOIC ACID, 2-ISOPROPENYL-5-METHYL-4-HEXEN-1-OL, AND A CARBOXYLATE ESTER THEREOF
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, (2021/10/22)
The present invention provides a process for preparing 2-isopropenyl-5-methyl-4-hexenoic acid of the following formula (4), comprising steps of: subjecting a Grignard reagent of the following general formula (1), wherein R1 represents a linear, branched, or aromatic monovalent hydrocarbon group having 1 to 8 carbon atoms, and X represents a chlorine atom, a bromine atom, or an iodine atom, and 1,1,1,3,3,3-hexamethyldisilazane to a deprotonation reaction to form a 1,1,1,3,3,3-hexamethyldisilazane derivative; and subjecting 2-methyl-3-buten-2-yl 3-methyl-2-butenoate of the following formula (3) to a rearrangement reaction in the presence of the 1, 1, 1,3,3,3-hexamethyldisilazane derivative to form 2-isopropenyl-5-methyl-4-hexenoic acid (4).
Structure-Function Studies of Artemisia tridentata Farnesyl Diphosphate Synthase and Chrysanthemyl Diphosphate Synthase by Site-Directed Mutagenesis and Morphogenesis
Lee, J. Scott,Pan, Jian-Jung,Ramamoorthy, Gurusankar,Poulter, C. Dale
supporting information, p. 14556 - 14567 (2017/10/24)
The amino acid sequences of farnesyl diphosphate synthase (FPPase) and chrysanthemyl diphosphate synthase (CPPase) from Artemisia tridentata ssp. Spiciformis, minus their chloroplast targeting regions, are 71% identical and 90% similar. FPPase efficiently and selectively synthesizes the "regular" sesquiterpenoid farnesyl diphosphate (FPP) by coupling isopentenyl diphosphate (IPP) to dimethylallyl diphosphate (DMAPP) and then to geranyl diphosphate (GPP). In contrast, CPPase is an inefficient promiscuous enzyme, which synthesizes the "irregular" monoterpenes chrysanthemyl diphosphate (CPP), lavandulyl diphosphate (LPP), and trace quantities of maconelliyl diphosphate (MPP) from two molecules of DMAPP, and couples IPP to DMAPP to give GPP. A. tridentata FPPase and CPPase belong to the chain elongation protein family (PF00348), a subgroup of the terpenoid synthase superfamily (CL0613) whose members have a characteristic α terpene synthase α-helical fold. The active sites of A. tridentata FPPase and CPPase are located within a six-helix bundle containing amino acids 53 to 241. The two enzymes were metamorphosed into one another by sequentially replacing the loops and helices of the six-helix bundle from enzyme with those from the other. Chain elongation was the dominant activity during the N-terminal to C-terminal metamorphosis of FPPase to CPPase, with product selectivity gradually switching from FPP to GPP, until replacement of the final α-helix, whereupon cyclopropanation and branching activity competed with chain elongation. During the corresponding metamorphosis of CPPase to FPPase, cyclopropanation and branching activities were lost upon replacement of the first helix in the six-helix bundle. Mutations of active site residues in CPPase to the corresponding amino acids in FPPase enhanced chain-elongation activity, while similar mutations in the active site of FPPase failed to significantly promote formation of significant amounts of irregular monoterpenes. Our results indicate that CPPase, a promiscuous enzyme, is more plastic toward acquiring new activities, whereas FPPase is more resistant. Mutations of residues outside of the α terpene synthase fold are important for acquisition of FPPase activity for synthesis of CPP, LPP, and MPP.
Photocatalytic Transfer Hydrogenolysis of Allylic Alcohols on Pd/TiO2: A Shortcut to (S)-(+)-Lavandulol
Takada, Yuki,Caner, Joaquim,Kaliyamoorthy, Selvam,Naka, Hiroshi,Saito, Susumu
supporting information, p. 18025 - 18032 (2017/12/08)
We report herein a regio- and stereoselective photocatalytic hydrogenolysis of allylic alcohols to form unsaturated hydrocarbons employing a palladium(II)-loaded titanium oxide; the reaction proceeds at room temperature under light irradiation without stoichiometric generation of salt wastes. Olefin and saturated alcohol moieties tolerated the reaction conditions. Hydrogen atoms were selectively incorporated into less sterically congested carbons of the allylic functionalities. This protocol allowed a short-step synthesis of (S)-(+)-lavandulol from (R)-(?)-carvone by avoiding otherwise necessary protection/deprotection steps.
Fungal mediated kinetic resolution of racemic acetates to (R)-alcohols using Fusarium proliferatum
Jadhav, Dipesh D.,Patil, Harshal S.,Chaya, Patil S.,Thulasiram, Hirekodathakallu V.
, p. 4563 - 4567 (2016/09/23)
Fungal mediated kinetic resolution of seven acyclic/aromatic acetates was achieved using Fusarium proliferatum to furnish (R)-alcohols in high enantiomeric excess (>95%). The kinetic resolution was established as one-pot two-step de-esterification/oxidation biocatalytic process. Further, the preparative scale synthesis of (R)-(+)-1-phenylethanol was accomplished through de-esterification/oxidation of (±)-1-phenylethyl acetate using the whole cell of F. proliferatum NCIM 1105.
METHOD OF MONITORING AND/OR CONTROLLING THYSANOPTERA
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Page/Page column 35-36, (2014/05/24)
The present invention provides a method of monitoring or controlling Thysanoptera (hereafter thrips) using a behaviour-modifying compound of Formula (1), wherein Formula (1) is: where R1 is a C2-C8 straight or branched alkenyl group and the * denotes a stereocentre. Suitably, the method involves providing the behaviour-modifying compound at a pre- determined location. Typically the behaviour-modifying compound is released or broadcast within an area infested (or potentially infested) by thrips. This can be achieved by using a lure or other release device comprising a compound of Formula (1), for example to attract the thrips to a trap.
Biomimetic total synthesis of (±)-doitunggarcinone A and (+)-garcibracteatone
Pepper, Henry P.,Tulip, Stephen J.,Nakano, Yuji,George, Jonathan H.
, p. 2564 - 2573 (2014/04/17)
A full account of our oxidative radical cyclization approach to the synthesis of garcibracteatone and doitunggarcinone A is presented. This includes the first enantioselective synthesis of garcibracteatone, which allowed the absolute configuration of the natural compound to be determined. The first synthesis of doitunggarcinone A is also described, which confirms our reassignment of the relative configuration of this molecule. Novel syntheses of monoterpene fragments used to construct the target molecules are also reported.
