- 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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- 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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- 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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