96154-47-1Relevant articles and documents
A Novel Synthesis of Sex Pheromone from the Longicorn Beetle (Psacothea hilaris)
He, Guo-Guo,Rao, Bao-Qi,Zhang, Tao,Zhang, Hong-Li,Bai, Hongjin,Du, Zhen-Ting
, p. 455 - 461 (2021/04/13)
Abstract: An asymmetric synthesis of (8Z,21R)-21-methylpentatriacont-8-ene, the sex pheromoneof the yellow-spotted longicorn beetle Psacotheahilaris, has been achieved using Evan’s induction as the keystep. Based on the asymmetric methylation product of chiral (R)-4-benzyl-1,3-oxazolidin-2-one, the carbon chainof the target molecule was assembled through aC5+C12+C11+C8sequence. (2R)-4-(Benzyloxy)-2-methylbutan-1-ol, which can be obtained fromγ-lactone following Evan’s protocol, was connected to aC12 alkyl group. The chiral methyl group remained thekey moiety (97% ee). After another Wittigreaction and catalytic hydrogenation step, the designed key intermediate(13R)-13-methylheptacosan-1-ol wasobtained. Finally, after oxidation and Wittig reaction, the synthesis of thetarget molecule was completed in 10 linear steps with an ultra-high overallyield of 36.2%.
Asymmetric total synthesis method of sex pheromone (R, Z)-21-methyl-8-tripentadecene of psacothea hilaris
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, (2020/12/30)
The invention discloses an asymmetric total synthesis method of sex pheromone (R, Z) 21-methyl-8-tripentadecene of psacothea hilaris, the method comprises the following steps: by using a compound 14 as an initial raw material, assembling a molecular carbon chain according to the sequence of C5+C12+C11+C8; firstly carrying out Wittig reaction with C12 quaternary phosphonium salt, and then carryingout another Wittig reaction and catalytic hydrogenation to obtain the key intermediate (R)-13-methylheptanoic acid-1-alcohol. Finally, after primary oxidation and Wittig reaction, obtaining the sex pheromone of the psacothea hilaris, wherein the total yield is 36.2%. According to the invention, the problems of lengthy synthesis steps, difficult resolution and low yield of non-chiral raw materialsin chiral pheromone synthesis are solved, and the asymmetric total synthesis of the sex pheromone (R,Z)21-methyl-8-tripentadecene of psacothea hilaris is completed. The method has the advantages of high yield, simple and convenient chemical operation and competitiveness in the aspect of cost control.
Syn-effect' in the diastereoselective alkylation of 3-[(E)-α,β-unsaturated-γ-substituted]-N-acyloxazolidinones
Jiménez, Jacqueline,Ramírez, Juáncarlos,Huelgas, Gabriela,Meléndrez, Ruth,Cabrera-Vivas, Blanca M.,Sansinenea, Estibaliz,Ortiz, Aurelio
, p. 4590 - 4597 (2015/06/08)
Synthetic methods for the formation of alkenes usually produce the E-alkene because it is more stable. However, in isomerization reaction (double bond migration) that takes place in α, β-unsaturated carbonyl compounds, when these carbonyl compounds are exposed to strong bases, furnish Z-alkenes highly stereoselective depending on the γ-substituent in the α, β-unsaturated carbonyl. This stereoselectivity can be attributed to the known Syn-effect. The synthetic value of this methodology is the achievement of chiral alcohol bearing an electron rich Z-alkene, as well as substituted, which was accomplished via removal of the oxazolidinone moiety under treatment with NaBH4, THF-H2O.
Total synthesis of attenols A and B
Reddy, B.V. Subba,Reddy, B. Phaneendra,Swapnil,Yadav
, p. 5781 - 5784 (2013/10/01)
A concise approach for the total synthesis of attenols A and B is described involving MacMillan's α-aminooxylation, Evan's asymmetric alkylation, Brown's allylation, and spiro-ketalization as key steps. This approach has successfully demonstrated the α-aminooxylation protocol for the construction of the anti-1,3-diol unit.
Highly stereocontrolled total synthesis of β-d-mannosyl phosphomycoketide: A natural product from mycobacterium tuberculosis
Li, Nan-Sheng,Scharf, Louise,Adams, Erin J.,Piccirilli, Joseph A.
, p. 5970 - 5986 (2013/07/26)
β-d-Mannosyl phosphomycoketide (C32-MPM), a naturally occurring glycolipid found in the cell walls of Mycobacterium tuberculosis, acts as a potent antigen to activate T-cells upon presentation by CD1c protein. The lipid portion of C32-MPM contains a C32-mycoketide, consisting of a saturated oligoisoprenoid chain with five chiral methyl branches. Here we develop several stereocontrolled approaches to assemble the oligoisoprenoid chain with high stereopurity (>96%) using Julia-Kocienski olefinations followed by diimide reduction. By careful choice of olefination sites, we could derive all chirality from a single commercial compound, methyl (2S)-3-hydroxy-2-methylpropionate (>99% ee). Our approach is the first highly stereocontrolled method to prepare C32-MPM molecule with >96% stereopurity from a single >99% ee starting material. We anticipate that our methods will facilitate the highly stereocontrolled synthesis of a variety of other natural products containing chiral oligoisoprenoid-like chains, including vitamins, phytol, insect pheromones, and archaeal lipids.
Diastereoselective alkylations of oxazolidinone vinylogous glycolates
Jiménez, Jacqueline,Meza-León, Rosa L.,Sartillo-Piscil, Fernando,Meléndez, Francisco J.,Sansinenea, Estibaliz,Ortiz, Aurelio
, p. 4775 - 4778 (2012/09/08)
A highly Z-selective isomerization (double bond migration) was observed when oxazolidinone vinylogous glycolate was exposed to a strong base to give N-acyl oxazolidinone, bearing an electron rich olefin. The corresponding enolate was exposed to alkyl halides to provide alkylated compounds on the γ-position with respect to OBn group, with high regioselectivity and moderate diastereoselectivity. However, the nature of the chiral oxazolidinone leads to a significant increase in the reaction diastereoselectivity. A stereospecific formation of cis-olefin was also observed in these alkylated compounds.
Synthetic studies on maitotoxin. 1. Stereoselective synthesis of the C D E F -ring system having a side chain
Morita, Masayuki,Ishiyama, Seishi,Koshino, Hiroyuki,Nakata, Tadashi
supporting information; experimental part, p. 1675 - 1678 (2009/04/10)
The stereoselective synthesis of the maitotoxin C D E F -ring system having a side chain has been accomplished through a convergent strategy. The key reactions include Horner-Wadsworth-Emmons coupling of the C D E -ring and the side chain and subsequent c
Synthesis of all 16 stereoisomers of pinesaw fly sex pheromones - Tools and tactics for solving problems in fluorous mixture synthesis
Dandapani, Sivaraman,Jeske, Mario,Curran, Dennis P.
, p. 9447 - 9462 (2007/10/03)
The application of fluorous mixture synthesis (FMS) for accessing natural products and their stereoisomers was validated by the total synthesis of all 16 stereoisomers of the pine sawfly sex pheromone. Four fluorous p-methoxybenzyl groups were used as tag
Total synthesis and biological evaluation of (+)-kalkitoxin, a cytotoxic metabolite of the cyanobacterium Lyngbya majuscula
White, James D.,Xu, Qing,Lee, Chang-Sun,Valeriote, Frederick A.
, p. 2092 - 2102 (2007/10/03)
(+)-Kalkitoxin, a metabolite of the marine cyanobacterium Lyngbya majuscula, was synthesized from (R)-2-methylbutyric acid, (R)-cysteine, and (3S, 4S, 6S)-3,4,6-trimethyl-8-(methylamino)octanoic acid. A key step in the synthesis was installation of the anti,anti methyl stereotriad by means of a tandem asymmetric conjugate addition of an organocopper species to an α,β-unsaturated N-acyl oxazolidin-2-one followed in situ by α-methylation of the resultant enolate. The thiazoline portion of kalkitoxin was assembled by titanium tetrachloride catalyzed cyclization of a vinyl substituted amido thiol.
Total synthesis of (+)-kalkitoxin
White, James D.,Lee, Chang-Sun,Xu, Qing
, p. 2012 - 2013 (2007/10/03)
The neurotoxic lipopeptide (+)-kalkitoxin was synthesized by a route which employed asymmetric organocopper conjugate addition followed by in situ enolate alkylation to install the anti,anti-1,2,4-trimethyl relationship of the toxin; the synthesis of kalkitoxin required sixteen steps and proceeded in 3% overall yield.
