- Ring A building blocks for taxoids and taxamycins
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The synthesis of a series of oxygenated cyclohexene ring A synthons 20, 22-27, 34, 36, and 37 that possess suitable functionality for further elaboration for taxoid synthesis are described. These compounds have been prepared from β-ionone by a series of oxidative and addition reactions or alternatively by Lewis acid catalyzed Diels-Alder cycloadditions with the oxygen-containing trimethyl substituted dienes 31 and 33. The syntheses of a series of oxygenated cyclohexene ring A synthons 20, 22-27, 34, 36, and 37 that possess suitable functionality for further elaboration for taxoid synthesis are described. These compounds have been prepared from β-ionone by a series of oxidative and addition reactions or alternatively by Lewis acid catalyzed Diels-Alder cycloadditions with the oxygen-containing trimethyl substituted dienes 31 and 33.
- Tjepkema, Michael W.,Wilson, Peter D.,Audrain, Helene,Fallis, Alex G.
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p. 1215 - 1224
(2007/10/03)
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- Condensation of β-Cyclocitral with Benzaldehyde
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β-Cyclocitral 1b condenses with benzaldehyde in the presence of base catalysts giving the 2-benzopyrans 4, 5 and 6, and in the presence of acid catalysts giving exclusively the aldehyde 7.The cyclocitrals 1a and 1b are both isomerized by strong base anion exchange resin, but their aldehyde-protected derivatives 2 and 3 are not.Some tests used to characterize the aldehydes and their condensation products are described.
- Frank, Arlen W.
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p. 549 - 554
(2007/10/02)
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