- Enantioselective Synthesis of the Sex Pheromone of Lichen Moth, Miltochrista calamine, and Its Diastereomer
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The synthesis of a Miltochrista calamine sex pheromone and its diastereomer has been developed. The key steps of the synthetic approach involved Evans' chiral auxiliaries and the addition of alkyne to aldehyde, which were firstly applied to prepare this sex pheromone and its diastereomer. The synthetic sex pheromone could be used to trap insects and study physiological and ecological questions of the lichen moth.
- Yuan, Gucheng,Liu, Jiawei,Yu, Shihang,Wang, Xueyang,Bian, Qinghua,Wang, Min,Zhong, Jiangchun
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supporting information
p. 80 - 83
(2021/10/05)
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- A New Asymmetric Synthesis of (S)-14-Methyloctadec-1-ene, the Sex Pheromone of the Peach Leafminer Moth
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Abstract: An asymmetric synthesis of 14-methyl-1-octadecene, the sex pheromone of thepeach leafminer moth has been achieved. Based on the asymmetric methylation ofchiral (S)-4-benzyloxazolidin-2-one, thecarbon chain of the target molecule was assembled through aC1+C10+C4+C3procedure. The γ-lactone was transformed into 4-(benzyloxy)butanoic acid andthen, with the induction of Evan’s template, a chiral methyl group wasintroduced to the position of the carboxylic group in 97percent de. After reduction and a couple of chemicaloperations, the designed key intermediate A1was obtained. The synthesis of another moiety was started from decane-1,10-diolwhich was selectively protected and oxidized. The long carbon chain wasinstalled according to a Wittig protocol. After deprotection, oxidization, andmethylenation, the target molecule was synthesized in 7 linear steps with anoverall yield of 30.3percent.
- Bai, Hongjin,Du, Zhen-Ting,He, Guo-Guo,Liu, Lu,Tang, Meng,Wei, Liang,Zhang, Tao
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p. 1089 - 1095
(2020/07/25)
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- Neutral iridium catalysts with chiral phosphine-carboxy ligands for asymmetric hydrogenation of unsaturated carboxylic acids
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We developed neutral iridium catalysts with chiral spiro phosphine-carboxy ligands (SpiroCAP) for asymmetric hydrogenation of unsaturated carboxylic acids. Different from the cationic Crabtree-type catalysts, the iridium catalysts with chiral spiro phosphine-carboxy ligands are neutral and do not require the use of a tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF?) counterion, which is necessary for stabilizing cationic Crabtree-type catalysts. Another advantage of the neutral iridium catalysts is that they have high stability and have a long lifetime in air. The new iridium catalysts with chiral spiro phosphine-carboxy ligands exhibit unprecedented high enantioselectivity (up to 99.4% ee) in the asymmetric hydrogenations of various unsaturated carboxylic acids, particularly for 3-alkyl-3-methylenepropionic acids, which are challenging substrates for other chiral catalysts.
- Yang, Shuang,Che, Wen,Wu, Hui-Ling,Zhu, Shou-Fei,Zhou, Qi-Lin
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p. 1977 - 1980
(2017/03/09)
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- Pheromone synthesis. Part 256: Synthesis of the four stereoisomers of 5,11-dimethylpentacosane, a new sex pheromone component of the male Galleria mellonella (L.), with high stereochemical purities as determined by the derivatization-HPLC analysis of the eight stereoisomers of 5,11-dimethyl-8-pentacosanol
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Abstract All the four stereoisomers of 5,11-dimethylpentacosane (>96.8% purity) were synthesized via the stereoisomers of 5,11-dimethyl-8-pentacosanol, whose stereoisomeric compositions could be determined precisely by their low temperature HPLC analysis after derivatization. 5,11-Dimethyl-8-pentacosanol was prepared by a Grignard reaction between 3-methylheptylmagnesium bromide and 4-methyloctadecanal, both of which were prepared from the commercially available enantiomers of citronellal (97-98% ee). Alternatively, (R)-3-methyl-1-heptanol could be prepared from methyl (R)-3-hydroxybutanoate (100% ee). Pd/C-catalyzed hydrogenation of a 5-methyl-1-alkene caused partial racemaization at C-5.
- Mori, Kenji,Akasaka, Kazuaki
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p. 4102 - 4115
(2015/06/02)
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- Cyclopropanol Methodology in the Synthesis of (4R)- and (4S)-4-Methyltetrahydro-2H-pyran-2-ones. Application in the Synthesis of Insect Pheromones with Methyl-Branched Carbon Skeleton
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A number of chiral methyl-branched building blocks have been synthesized starting from (4S)-4-methyltetrahydro-2H-pyran-2-one, and the possibility for using them for the preparation of mealworm beetle, rhinoceros beetle, and earth-boring dung beetle phero
- Mineeva
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p. 341 - 351
(2015/05/04)
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- Cyclopropane intermediates in the synthesis of chiral alcohols with methyl-branched carbon skeleton. Application in the synthesis of insect pheromones
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Several chiral building blocks, (2R)-2-methylundec-10-en-1-ol, (3R)-3-methylheptan-1-ol, and (4R)-4-methyloctan-1-ol, have been synthesized using cyclopropane intermediate products. It has been shown that the obtained chiral alcohols can be used in the sy
- Kovalenko,Mineeva
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p. 934 - 942
(2014/10/15)
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- Lipase-catalyzed preparation of optically active isomers of cyclamen aldehyde
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The optically active isomers of cyclamen aldehyde 1a were synthesized from a chiral intermediate prepared by lipase-catalyzed enantioselective transesterification of a prochiral diol with vinyl acetate. The absolute configuration of the enantiomer of 1a w
- Kawasaki, Masashi,Goto, Michimasa,Hu, Dawei,Toyooka, Naoki,Kometani, Tadashi
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- Stereospecific inversion of secondary tosylates to yield chiral methyl-branched building blocks, applied to the asymmetric synthesis of leafminer sex pheromones
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All four of the possible stereoisomers of 5,9-dimethylheptadecane, the major sex pheromone component secreted by female moths of the mountain-ash bentwing (Leucoptera scitella), were synthesized by the coupling of two chiral blocks with a methyl branch at the 2- or 3-position. The blocks were prepared by applying the stereospecific inversion of secondary tosylates, which were derived from (R)- and (S)-propylene oxide, and their enantiopurities were confirmed by chiral HPLC analysis.
- Taguri, Tomonori,Yamakawa, Rei,Fujii, Toru,Muraki, Yuta,Ando, Tetsu
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p. 852 - 858
(2012/09/22)
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- (5R,7R)-5-Methylheptadecan-7-ol: A novel sex pheromone component produced by a female lichen moth, Miltochrista calamina, in the family Arctiidae
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A methyl-branched heptadecanol was found in the pheromone gland extract of a female lichen moth, Miltochrista calamina (Arctiidae, Lithosiinae). GC-MS analyses of the alcohol and a hydrocarbon derived from it by subsequent treatments with methanesulfonyl chloride and LiAlD4 in microscale reactions indicated 5-methylheptadecan-7-ol (1) as one possible structure. The four stereoisomers of 1 in a ratio of 4:4:1:1 were prepared from (S)-b-citronellol with 60% ee, and were separated by a combination of achiral and chiral HPLC columns. The absolute configuration of each isomer was determined by the comparison with the chromatographic behaviors of other samples synthesized by a different scheme, which applied the Jacobsen hydrolytic kinetic resolution of racemic 1,2-epoxydodecane to fix the configuration of the 7-hydroxy group. Only the (5R,7R)-isomer attracted male moths; thus, we concluded that M. calamina females secrete (5R,7R)-1 as a sex pheromone, indicating a new chemical class of lepidopteran female sex pheromones.
- Yamakawa, Rei,Kiyota, Ryutaro,Taguri, Tomonori,Ando, Tetsu
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p. 5808 - 5811
(2011/12/14)
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- Asymmetric conjugate silyl transfer in iterative catalytic sequences: Synthesis of the C7-C16 fragment of (+)-neopeltolide
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Matched or mismatched, that is not the question! The anti,anti configuration of the C7- C16 fragment of (+)-neopeltolide is stereoselectively installed in an iterative sequence of catalyst-controlled Si group and Me group transfers, even with mismatched selectivity in the former (Si=Me2PhSi, see scheme; TBS=tert-butyldimethylsilyl).
- Hartmann, Eduard,Oestreich, Martin
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supporting information; experimental part
p. 6195 - 6198
(2010/11/17)
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- The organocatalytic addition of bis(arylsulfonyl)methane to α,β-unsaturated aldehydes and the synthesis of optically-enriched 3-methyl-alkanols
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An indirect organocatalytic method for the β-methylation of α,β-unsaturated aldehydes that involves the addition of bis(arylsulfonyl)methane catalyzed by prolinol derivatives and further elimination of the chameleonic sulfonyl groups is presented. The Roy
- Garcia Ruano, Jose Luis,Marcos, Vanesa,Aleman, Jose
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supporting information; experimental part
p. 4435 - 4437
(2009/12/29)
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- (S,S)-(+)-pseudoephedrine as chiral auxiliary in asymmetric conjugate addition and tandem conjugate addition/α-alkylation reactions
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(Chemical Equation Presented) Organolithium reagents undergo highly regio- and diastereoselective 1,4-addition to (S,S)-(+)-pseudoephedrine enamides furnishing the corresponding β-alkyl-substituted adducts in excellent yields and diastereoselectivities. In addition, the intermediate lithium enolates generated after the conjugate addition step undergo a highly diastereoselective alkylation reaction, furnishing α,β-dialkyl- substituted amides in high yields. The obtained adducts have been converted into chiral nonracemic β-alkyl- and α,β-dialkyl-substituted carboxylic acids and γ-alkyl- and β,γ-dialkyl-substituted alcohols using very simple and high-yielding procedures.
- Reyes, Efraim,Vicario, Jose L.,Carrillo, Luisa,Badia, Dolores,Uria, Uxue,Iza, Ainara
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p. 7763 - 7772
(2007/10/03)
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- (R)-4-menthenone in the synthesis of optically pure sex pheromone of the peach leafminer moth (Lyonetia clerkella)
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The synthesis of (14S)-methyloctadec-1-ene, sex pheromone of the peach leafminer moth (Lyonetia clerkella), is described to demonstrate a new potential of the synthetic use of (R)-4-menthenone.
- Kharisov,Latypova,Talipov,Muslukhov,Ishmuratov,Tolstikov
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p. 2267 - 2269
(2007/10/03)
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- Regio- and stereochemical study of sex pheromone of pine sawfly; Diprion nipponica
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Regio- and stereoisomers of 1,2,ω-trimethyldecyl propionate (ω = 5-9) were prepared from stereochemically pure chiral building blocks as sex pheromone candidates of a pine sawfly; Diprion nipponica. Among the synthesized candidates, (1S,2R,8S)-1,2,8-trimethyldecyl propionate was found to be the sex pheromone of D. nipponica, based on compatibility of its GC-MS data with that of the extract of females, and its significantly high pheromone activity in a field bioassay. The field bioassay of the synthesized compounds also revealed that (1S,2R,SR)-1,2,8-trimethyldecyl propionate, (1S,2R,7S)-1,2,7-trimethyldecyl propionate, and (1S,2R,6S)-1,2,6-trimethyldecyl propionate could attract male sawflies to some extent as pheromone mimics.
- Tai, Akira,Syouno, Emi,Tanaka, Kazuki,Fujita, Morifumi,Sugimura, Takashi,Higashiura, Yasutomo,Kakizaki, Masashi,Hara, Hideho,Naito, Tikahiko
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p. 111 - 121
(2007/10/03)
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- Semiochemicals of the Scarabaeinae: VI. Identification of EAD-active constituents of abdominal secretion of male dung beetle, Kheper nigroaeneus.
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Using gas chromatography with flame ionization detection (FID) and electroantennographic detection (EAD) in parallel, and employing chiral and achiral capillary columns, three constituents of the abdominal sex-attracting secretion of male Kheper nigroaeneus dung beetles were found to elicit reproducible EAD responses in male and female K. nigroaeneus antennae. One of these constituents is present in the secretion in such a small quantity that it could not be detected by FID, and it was not identified. The other constituents were identified as 3-methylindole (skatole) and (R)-(+)-3-methylheptanoic acid.
- Burger,Petersen
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p. 501 - 513
(2007/10/03)
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- Total synthesis of HUN-7293
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The first total synthesis of the cyclic heptadepsipeptide HUN-7293 (1), a potent inhibitor of cell adhesion molecule expression exhibiting anti-inflammatory properties, is detailed. The most effective approach relied on an unusually efficient macrocyclization with the formation of the MLEU3 - LEU4 secondary amide that potentially benefits from intramolecular H-bonding preorganization of the acyclic substrate. The requisite linear depsipeptide was convergently assembled with the late stage introduction of the linking ester enlisting a Mitsunobu esterification that occurs with inversion of the DGCN α-center permitting the utilization of a readily available L-amino acid precursor to the D α-hydroxy carboxylic acid residue. An alternative and similarly attractive approach of direct macrolactonization of a substrate necessarily incorporating a D-DGCN subunit proved viable albeit less effective. Biological evaluation in cellular assays for vascular adhesion molecule expression confirmed that synthetic HUN-7923 (1) is essentially indistinguishable from the naturally occurring cyclodepsipeptide.
- Boger, Dale L.,Keim, Holger,Oberhauser, Berndt,Schreiner, Erwin P.,Foster, Carolyn A.
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p. 6197 - 6205
(2007/10/03)
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- Enantioselective carbometalation of cinnamyl derivatives: New access to chiral disubstituted cyclopropanes - Configurational stability of benzylic organozinc halides
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A stoichiometric or catalytic amount of (-)-sparteine can serve asa promoter for the enantioselective carbolithiation of cinnamyl derivatives by primary and secondary organolithium compounds. The enantiofacial choice of the addition reaction is dependent on the stereochemistry of the initial double bond. The resulting benzylic organolithium compounds can be derivatized to a linear phenylated chain that bears two contiguous stereogenic centers with given configurations. The use of the dimethyl acetal of the (E)-cinnamyl alcohol allows the highest enantioselective carbolithiation and by simply warming the reaction mixture to room temperature, the resulting benzylic organo-lithium intermediate undergoes a 1,3-elimination to give the chiral disubstituted cyclopropane in high enantiomeric excess (90-95% ee). Another significant finding is the observation that the Li-Zn transmetalation in a benzylic species occurs with inversion of configuration, and the corresponding acyclic benzylic zinc halides have observable configurational stability at - 30°C.
- Norsikian, Stephanie,Marek, Ilan,Klein, Sophie,Poisson, Jean F.,Normant, Jean F.
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p. 2055 - 2068
(2007/10/03)
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- Application of (2R,3R)-dihydroxy-1,2,3,4-tetrahydronaphthalene to asymmetric synthesis
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(2R,3R)-Dihydroxy-tetrahydronaphthalene, prepared via an efficient chemoenzymatic procedure from naphthalene, has been successfully tested, as a chiral auxiliary in diastereoselective conjugate additions of lithium dialkylcuprates to α,β-unsaturated ester
- Orsini, Fulvia,Rinaldi, Sabina
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p. 1039 - 1048
(2007/10/03)
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- Enantioselective carbolithiation of β-alkylated styrene
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Stoichiometric or catalytic amounts of (-) sparteine serve as promoter for enantioselective carbolithiation of β-alkylated, non functionalized styrene.
- Norsikian, Stephanie,Marek, Ilane,Normant, Jean-F.
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p. 7523 - 7526
(2007/10/03)
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- Sterically constrained tricyclic 2-oxazolidinone as excellent chiral auxiliary
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A new class of conformationally rigid 2-oxazolidinones with effectively bulky substituents, derived from the [4+2] cycloadduct of cyclopentadiene and a-oxazolone, serve as extremely powerful chiral auxiliaries for asymmetric alkylations, Diels-Alder reactions and conjugate addition reactions.
- Nakamura, Taiju,Hashimoto, Noriaki,Ishizuka, Tadao,Kunieda, Takehisa
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p. 559 - 562
(2007/10/03)
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- A practical synthesis of 3(S)-methyl-heptanoic acid from (S)-citronellol
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Chiral 3-methyl-heptanoic acid is readily accessible by functional group manipulation of optically active citronellol. In principle, this approach is general and could be applied to the synthesis of chiral 3-methyl-alkanoic acids seven carbon atoms in length and longer.
- Breitenbach, Ralph,Chiu, Charles K.-F.,Massett, Stephen S.,Meltz, Morgan,Murtiashaw, C. William,Pezzullo, Susan L.,Staigers, Thomas
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p. 435 - 442
(2007/10/03)
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- Optical Isomers of 3,13-Dimethylheptadecane: Sex Pheromone Components of the Western False Hemlock Looper, Nepytia freemani (Lepidoptera: Geometridae)
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(3S,13R)-3,13-Dimethylheptadecane [(3S,13R)-3,13-dime-17Hy] is the major pheromone component of the western false hemlock looper (WFHL), Nepytia freemani. In comparative gas chromatographic-electroantennographic detection (GC-EAD) analyses of stereoselectively synthesized isomers, 1 pg of (3S,13R)-dime-17Hy elicited significantly stronger electrophysiological responses by male WFHL antennae than did 1 pg of separately injected (3R,13R)-, (3R,13S)- or (3S,13S)-3,13-dime-17Hy. In field experiments with individually tested stereoisomers, (3S,13R)-3,13-dime-17Hy was the only stereoisomer to attract males, but the four-stereoisomer blend was 3.6 times more attractive. Quaternary and all binary combinations of (3S,13R)-3,13-dime-17Hy with the other stereoisomers were equally attractive, suggesting that synergistic behavioral activity in WFHL resided with either one of (3R,13R)-, (3R,13S)-, or (3S,13S)-3,13-dime-17Hy. Because optical isomers of (di)methylhydrocarbons do not separate on currently available columns, it remains unknown whether female WFHL also produce a four-stereoisomer pheromone blend. Substitutionality of pheromone stereoisomers without loss of behavioural activity has not previously been reported, but favorably compares with the concept of pheromone redundancy that was first suggested for the multiple pheromone component blend of the cabbage looper moth, Trichoplusia ni.
- King, G. G. Skip,Gries, Regine,Gries, Gerhard,Slessor, K. N.
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p. 2027 - 2046
(2007/10/03)
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- Dispiroketals in synthesis (Part 16): Functionalised dispiroketals as new chiral auxiliaries; the synthesis of dihydroxylated dispiroketals in optically pure form and their application as bifunctional , C2-symmetrical, chiral auxiliaries for highly stereoselective Michael additions
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A range of rigid, architecturally complex diols derived from dispiroketals have been synthesised.A bifunctional, C2-symmetrical, chiral auxiliary derived from these dihydroxylated dispiroketals has been used to induce a high degree of asymmetry in Michael additions of cuprates to a variety of di-α,β-unsaturated ester systems.
- Bezuidenhoudt, Barend C. B.,Castle, Grant H.,Innes, Jean E.,Ley, Steven V.
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p. 184 - 194
(2007/10/02)
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- Dispiroketals in Synthesis (Part 14): Functionalised Dispiroketals as New Chiral Auxiliaries; Highly Stereoselective Michael Additions to a Bifunctional, C2-Symmetrical Chiral Auxiliary.
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A bifunctional, C2-symmetrical chiral auxiliary derived from dihydroxylated dispiroketals has been used to induce a high degree of asymmetry in Michael additions of cuprates to a variety of di-α,β-unsaturated ester systems.
- Castle, Grant H.,Ley, Steven V.
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p. 7455 - 7458
(2007/10/02)
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- Synthesis and reactivity of chiral alkoxyallenes prepared by carbocupration of propargylic acetals.
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Chiral propargylic acetals are easily prepared with a chiral diol having a C2 axis of symmetry.They react highly diastereoselectively with Grignard reagents, under CuI catalysis, to afford axially chiral alkoxy allenes.The process is believed to involve a syn addition of the organometallic reagent across the triple bond, followed by a selective anti β-elimination of the alkoxy moiety next to the pseudoaxial substituent of the acetal ring.Although these chiral alkoxy allenes slowly racemize in the presence of CuI salts it is possible to slow down this processby addition of trivalent phosphorus ligands.In the absence of any copper salt, such preformed alkenyl organometallic reagents (Li, Mg) also undergo a highly diastereoselective β-elimination (de > 90percent).These chiral alkoxy allenes react further with lithium dialkyl cuprate to afford the E or Z enol ether (according to the reaction condition) leading, after hydrolysis, to chiral β-disubstituted aldehydes. Key Words: chiral diols / propargylic acetals / alkoxy allenes / organocuprates / enol ether E and Z / β-disubstituted aldehydes
- Marek, I.,Alexakis, A.,Mangeney, P.,Normant, J. F.
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p. 171 - 190
(2007/10/02)
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- Highly diastereoselective additions of organocopper reagents to 2-exo-bornyl crotonates
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Iodotrimethylsilane-activated butylcopper adds to the chiral bornyl crotonates 1-3 in high yields and with good to excellent diastereoselectivities. In the present investigation, these reactions are compared with additions of lithium butylcuprates of vari
- Bergdahl, Mikael,Nilsson, Martin,Olsson, Thomas,Stern, Kaye
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p. 9691 - 9702
(2007/10/02)
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- Asymmetric conjugate addition of organometallic reagents to chiral α,β-unsaturated esters
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Asymmetric conjugate addition to α,β-unsaturated ester was studied using four kinds of cyclic diols (1c-4c) as chiral auxiliaries. Among the tested substrates, (R,R)-cyclohexane-1,2-diol derivatives (6a-c) and (1R,2S)-2-hydroxymethylcyclopentanol derivative (7a) showed high and reverse diastereoselectivity in conjugate addition by organocuprates (R2CuLi) and/or Grignard reagents in the presence of copper iodide (RMgBr + CuI), respectively.
- Fang,Ogawa,Suemune,Sakai
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p. 389 - 398
(2007/10/02)
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- Stereoselective conjugate addition of TMSI-activated butylcopper to 1-(R)-endo-(1-naphthyl)bornyl crotonate
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Conjugate addition of butylcopper/iodotrimethylsilane to naphthylbornyl crotonate (1) at -60 deg C gives 1-bornyl heptanoate (2) in 93percent yield and 98percent diastereomeric excess.The addition of TMSI-activated butylcopper is faster at -60 deg C than that of lithium dibutylcuprate (LiBu2Cu).
- Bergdahl, Mikael,Nilsson, Martin,Olsson, Thomas
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p. C19 - C22
(2007/10/02)
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- Peptide immunostimulants
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Peptide compounds of formula 1, pharmaceutically acceptable base salts thereof, pharmaceutical compositions and their use as antiinfective agents where R1 is alkyl, cycloalkyl or cycloalkylmethyl; R2 is hydrogen or alkyl and R3 is hydroxy or an amino acid residue of the formula where X is hydrogen, alkyl or hydroxymethyl and nis an integer of 0 to 4 and R4 and R5 are alkyl, hydrogen, benzyl or cyclohexylmethyl.
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- SIMPLE CAMPHOR DERIVATIVES AS CHIRAL AUXILIARIES FOR ASYMMETRIC CONJUGATE ADDITION
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The chiral enoates, 4, readily available in two simple steps from (+)-camphor, undergo asymmetric conjugate addition with the Gilman reagent LiBu2Cu.Chemical yields are high (70-90percent) and in the case of the naphthyl-substituted enoate 4e excellent diastereoselectivity (95percent d.e.) is observed. 3-Methyl-heptan-1-ol of correspondingly high enantiomeric purity is obtained by reduction of the conjugate adduct with lithium aluminium hydride.
- Somfai, Peter,Tanner, David,Olsson, Thomas
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p. 5973 - 5980
(2007/10/02)
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- Pheromone Syntheses, LXXVII. - New Synthesis of the Enantiomers of 14-Methyl-1-octadecene, the Pheromone of Lyonetia clerkella L.
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The synthesis of the title compounds (R)-1 and (S)-1 from (R)-citronellic acid (R)-2 is described.
- Mori, Kenji,Kato, Minoru
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p. 2083 - 2087
(2007/10/02)
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