- Synthesis of functionalized 2,3-dihydroisoxazoles by domino reactions in water and unexpected ring-opening reactions of 2,3-dihydroisoxazoles
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α,α-Dicyanoolefins react with hydroxylamine to afford 2,3-dihydroisoxazoles (2,3-dihydroisoxazoles can be easily isolated by filtration) in excellent yields under mild and environmentally benign conditions. A one-pot reaction in tandem with an unexpected ring-opening of 2,3-dihydroisoxazoles has been developed as well.
- Li, Ping,Teng, Bo-Tao,Jin, Fa-Gen,Li, Xin-Sheng,Zhu, Wei-Dong,Xie, Jian-Wu
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p. 244 - 247
(2012/01/19)
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- Method for making bicycle lactones from beta, gamma unsaturated cyclic nitriles
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A method for making a bicyclic lactone comprising heating under aqueous acidic conditions a beta, gamma unsaturated cyclic nitrile and an aldehyde, for a length of time sufficient to convert at least a portion of the reactants to a bicyclic lactone of the formula STR1 wherein R3 is --H; R4, R5, and R6 are independently selected from the group consisting of --H, --CH3 ; R2 is selected from the group consisting of --H, --CH3, and --CH3, and --C2 H5 ; R8 is --H or --CH3 ; m is an integer from 1 to 5; o is 0, 1, 2, or 3; and p is 0, 1, or 2; provided that the sum of m+o+p is an integer from 3 to 5; either R3 or R8 together with R7 represents a carbon-carbon bond. The method uses commercially available and relatively inexpensive raw materials as reactants.
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- CINETIQUE ET MECANISME DE LA REACTION DE KNOEVENAGEL DANS LE BENZENE-2 REACTION DU MALONITRILE ET DE LA (+) METHYL-3 CYCLOHEXANONE EN PRESENCE D'UNE AMINE PRIMARIE PURE ET DE SON MELANGE AVEC L'ACIDE ACETIQUE
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The kinetics of the reaction of (+)-3-methyl cyclohexanone with malonitrile were studied in benzene at 25 deg C, in the presence of hexylamine-acetic acid mixtures.Hexylamine gives an imine with cyclohexanone in an acid-catalyzed step.This imine then reacts quickly with malononitrile.A rate law of zero order in malononitrile is observed.Separate kinetic results obtained for the formation of the imine and for the imine-malonitrile reaction support this mechanism.Without acetic acid, a complex rate law is observed; hexylamine acts mainly as a basic catalyst.Primary amine-carboxylic acid was used as a catalyst in Knoevenagel reaction, often giving an increase in yield and a diminution in the reaction time compared with the more commonly used catalysts: piperidine, β-alanine, AcOH-AcONH4.
- Guyot, J.,Kergomard, A.
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p. 1167 - 1179
(2007/10/02)
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- LONG-ACTING CONTRACEPTIVE AGENTS: LEVONORGESTREL ESTERS OF UNSATURATED ACIDS
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Esters of levonorgestrel (13β-ethyl-17α-ethynyl-17β-hydroxygon-4-en-3-one) with a variety of unsaturated carboxylic acids have been synthesized for evaluation as potential long-acting, injectable contraceptive agents.
- Wan, A. S. C.,Ngiam, T. L.,Leung, S. L.,Go, M. L.,Francisco, C. G.,et al.
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p. 339 - 348
(2007/10/02)
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