111767-94-3Relevant academic research and scientific papers
Asymmetric conjugate addition of organometallic reagents to chiral α,β-unsaturated esters
Fang,Ogawa,Suemune,Sakai
, p. 389 - 398 (1991)
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.
Enantioselective Synthesis of the Sex Pheromone of Lichen Moth, Miltochrista calamine, and Its Diastereomer
Yuan, Gucheng,Liu, Jiawei,Yu, Shihang,Wang, Xueyang,Bian, Qinghua,Wang, Min,Zhong, Jiangchun
, p. 80 - 83 (2021/10/05)
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.
A New Asymmetric Synthesis of (S)-14-Methyloctadec-1-ene, the Sex Pheromone of the Peach Leafminer Moth
Bai, Hongjin,Du, Zhen-Ting,He, Guo-Guo,Liu, Lu,Tang, Meng,Wei, Liang,Zhang, Tao
, p. 1089 - 1095 (2020/07/25)
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.
Neutral iridium catalysts with chiral phosphine-carboxy ligands for asymmetric hydrogenation of unsaturated carboxylic acids
Yang, Shuang,Che, Wen,Wu, Hui-Ling,Zhu, Shou-Fei,Zhou, Qi-Lin
, p. 1977 - 1980 (2017/03/09)
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.
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
Mori, Kenji,Akasaka, Kazuaki
, p. 4102 - 4115 (2015/06/02)
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.
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
Mineeva
, p. 341 - 351 (2015/05/04)
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
Cyclopropane intermediates in the synthesis of chiral alcohols with methyl-branched carbon skeleton. Application in the synthesis of insect pheromones
Kovalenko,Mineeva
, p. 934 - 942 (2014/10/15)
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
Lipase-catalyzed preparation of optically active isomers of cyclamen aldehyde
Kawasaki, Masashi,Goto, Michimasa,Hu, Dawei,Toyooka, Naoki,Kometani, Tadashi
, p. 27 - 33 (2013/10/22)
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
Stereospecific inversion of secondary tosylates to yield chiral methyl-branched building blocks, applied to the asymmetric synthesis of leafminer sex pheromones
Taguri, Tomonori,Yamakawa, Rei,Fujii, Toru,Muraki, Yuta,Ando, Tetsu
, p. 852 - 858 (2012/09/22)
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.
(5R,7R)-5-Methylheptadecan-7-ol: A novel sex pheromone component produced by a female lichen moth, Miltochrista calamina, in the family Arctiidae
Yamakawa, Rei,Kiyota, Ryutaro,Taguri, Tomonori,Ando, Tetsu
, p. 5808 - 5811 (2011/12/14)
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.
