- Enantioselective iridium-catalyzed carbonyl isoprenylation: Via alcohol-mediated hydrogen transfer
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Highly enantioselective iridium catalyzed carbonyl (2-vinyl)allylation or "isoprenylation" is achieved via hydrogen auto-transfer or 2-propanol-mediated reductive coupling from primary alcohol or aldehyde reactants, respectively. Using this method, asymmetric total syntheses of the terpenoid natural products (+)-ipsenol and (+)-ipsdienol were achieved.
- Xiang, Ming,Luo, Guoshun,Wang, Yuankai,Krische, Michael J.
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- Enantioselective synthesis of ipsenol and ipsdienol using a (2-bromoallyl)borane derivative
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(S)-(-)-Ipsenol and (S)-(+)-ipsdienol, a major component of the sex pheromone of the bark beetle, and their enantiomers were prepared enantioselectively using tartrate esters of (2-bromoallyl)boronic acid in the key step.
- Yamamoto, Yasunori,Hara, Shoji,Suzuki, Akira
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- A new synthesis of the enantiomers of ipsdienol, the pheromone of the Ips bark beetles
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The enantiomers (~96% e.e.) of ipsdienol (2-methyl-6-methylene-2,7-octadien-4-ol, 1a) were synthesized from the enantiomers of serine (5) in 16-21% overall yield in 8 steps.
- Mori,Takikawa
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- Enantioselective Isoprenylboration Reaction of Aldehydes Catalyzed by a Chiral Phosphoric Acid
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The BINOL-derived chiral phosphoric acid (R)-TRIP is utilized as an organocatalyst in the asymmetric isoprenylboration reaction of aldehydes, wherein hydrogen-bond interactions play a key role in the control of enantioselectivity. A wide arrays of enantioenriched dienyl homoallyl alcohols, including two natural products (?)-Ipsdienol and (?)-Ipsenol, have been successfully constituted. The synthetic application to chiral isoprenylated isobenzofuranone, vinyloxirane and cyclohexene derivatives has also been disclosed. (Figure presented.).
- Zhang, Yu-Long,He, Bo-Jun,Xie, Yi-Wen,Wang, Yu-Hao,Wang, Yi-Long,Shen, Yong-Cun,Huang, Yi-Yong
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supporting information
p. 3074 - 3079
(2019/05/15)
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- Stereoselective synthesis of (R)- and (S)-ipsdienols, pheromone components of bark beetles of the Ips family
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Abstract-(R)- and (S)-Ipsdienols, components of pheromones of bark beetles of the Ips family, were synthesized with high enantiomeric purity (>98%) from 8-chloro-2-methyl-6-methylideneoct-2-en-4-ol prepared from ethyl 3-chloropropionate via cyclopropanati
- Kovalenko,Matyushenkov
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p. 1168 - 1172
(2013/01/15)
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- Catalytic asymmetric allylic transfer reactions for the Enantioselective synthesis of dienyl and enynyl alcohols
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Efficient catalytic asymmetric allylic transfer reactions of achiral aldehydes with 2-ethynyl- and 2-ethenyl-2-propenyl-stannane promoted by BINOL-TiIV complex with synergetic reagent are achieved for the synthesis of homoenynyl- and dienyl alcohols with high levels of enantioselectivity. The range of enantioselectivity is 84-99% ee with good chemical yields. The application of catalytic asymmetric dienylation in a single operation was exemplified by the enantioselective synthesis of naturally occurring (-)-Ipsdienol and (-)-Ipsenol.
- Yu, Chan-Mo,Jeon, Miyoo,Lee, Jae-Young,Jeon, Junha
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p. 1143 - 1148
(2007/10/03)
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- Intermediates useful for the chiral isoprenylation of aldehydes
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An improved process for preparing either optically pure enantiomer of the bark beetle pheromones ipsenol and ipsdienol is provided. The process is also applicable to the condensation of aldehydes of widely varying properties to the corresponding chiral alcohol. This invention also concerns novel intermediates R'2 B(2'-isoprenyl) wherein R' is isopinocampheyl, 2-isocaranyl and 4-isocaranyl.
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- Chiral synthesis VIA organoboranes. 26. An efficient synthesis of isoprenyl derivatives of borane - Valuable reagents for the isoprenylboration of aldehydes. A convenient route to both enantiomers of ipsenol and ipsdienol in high optical purity
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Preparation of B-isoprenyldialkylboranes is achieved by adopting the Brandsma modification of the Schlosser procedure, namely metallation of isoprene with potassium 2,2,5,5-tetramethylpiperidide followed by sequential treatment with 5-methoxydialkylborane and boron trifluoride-etherate. These reagents are used for the convenient isoprenylation of aldehydes. Reaction of isovaleraldehyde and β, β-dimethylacrolein with B2′isoprenyldiisopinocampheylborane provides both ipsenol and ipsdienol, respectively in 65% yields and 96% ee.
- Brown, Herbert C.,Randad, Ramnarayan S.
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p. 4463 - 4472
(2007/10/02)
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- B-2'-ISOPRENYLDIISOPINOCAMPHEYLBORANE: AN EFFICIENT REAGENT FOR THE CHIRAL ISOPRENYLATION OF ALDEHYDES. A CONVENIENT ROUTE TO BOTH ENANTIOMERS OF IPSENOL AND IPSDIENOL
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B-2'-Isoprenyldiisopinocampheylborane is prepared by metallation of isoprene with potassium 2,2,5,5-tetramethylpiperidide followed by sequential treatment with B-methoxydiisopinocampheylborane and boron trifluoride-etherate.Condensation of this reagent with aldehydes provides isoprenylated chiral alcohols.This methodology is utilized for an efficient one-pot synthesis of both enantiomers of the pheromones of the bark beetle Ips paraconfusus Lanier, ipsenol and ipsdienol in 96percent ee and 65percent isolated yields.
- Brown, Herbert C.,Randal, Ramnarayan S.
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p. 455 - 458
(2007/10/02)
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- New Three-Step Syntheses of Racemic and Optically Active Ipsdienol from Myrcene
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2-Methyl-6-methylene-3,7-octatriene-2-ol(6), which is readily available from photooxidation of myrcene (5), was transformed into racemic and optically active ipsdienol (2).Treatment of the trienol 6 with perchloric acid in acetic acid yielded ipsdienyl acetate which on hydrolysis gave racemic ipsdienol (2) in 83percent overall yield.Oxidation of the trienol 6 with pyridinium chlorochromate in the presence of pyridine hydrochloride furnished 2-methyl-6-methylene-2,7-octadien-4-one (8) in 43percent yield.Reduction of this ketone with lithium aluminium hydride partially decomposed by one molar eg. each of ethanol and either (R)-(+)- or (S)-(-)- 2,2'-dihydroxy-1,1'-binaphthyl gave (R)-(-)- or (S)-(+)-ipsdienol (2' or 2", respectively) in 70percent yield and 60-65percent ee.
- Baeckstroem, P.,Bjoerkling, F.,Hoegberg, H.-E.,Norin, T.
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