Cascade condensation, cyclization, intermolecular dipolar cycloaddition by multi-component coupling and application to a synthesis of (±)-crispine A
作者:Iain Coldham、Samaresh Jana、Luke Watson、Nathaniel G. Martin
DOI:10.1039/b822743h
日期:——
A general approach for the synthesis of various nitrogen-containing heterocyclic compounds is described using an intermolecular dipolarcycloaddition reaction of azomethine ylides and nitrones. Stabilized and non-stabilized azomethine ylide dipoles or the related nitrones were generated by condensation of 4-, 5- or 6-halo-aldehydes with a readily available amino-acid, amino-ester or hydroxylamine to
Cascade cyclization intermolecular dipolar cycloaddition by multi-component couplings—synthesis of indolizidines and pyrrolizidines
作者:Iain Coldham、Samaresh Jana、Luke Watson、Christopher D. Pilgram
DOI:10.1016/j.tetlet.2008.07.010
日期:2008.9
hydroxylamine), an alkene or alkyne dipolarophile and an aldehyde bearing a halide as a leaving group has been developed. Condensation of the amine with the aldehyde and cyclization (intramolecular N-alkylation) provides, after decarboxylation or deprotonation, a cyclic azomethine ylide (or nitrone) that undergoes intermolecular dipolar cycloaddition with the dipolarophile. This sets up, in a single step, the
Sulphone-based elimination reactions in synthesis. Part 1. Moenocinol
作者:Philip Kocienski、Michael Todd
DOI:10.1039/p19830001777
日期:——
The fluoride-induced elimination of a β-phenylsulphonylsilane and the reductive elimination of a β-oxy sulphone are key olefin-forming reactions in a synthesis of moenocinol [(2Z, 6E, 13E)-3,8,8,14,18-pentamethyl-11-methylenenonadeca-2,6,13,17-tetraen-1-ol].
One-Pot Synthesis of 3,3-Dimethylpyrrolidine-2-carbonitriles from 4-Chloro-2,2-dimethylbutanal in Water
作者:Norbert De Kimpe、Matthias D’hooghe、Berten Van Driessche
DOI:10.3987/com-08-s(f)1
日期:——
Treatment of 4-chloro-2,2-dimethylbutanal, prepared in high yield by means of a three-step procedure starting from ethyl isobutyrate, with successively sodium bisulphite, a primary amine and potassium cyanide in water afforded novel 1-alkyl- and 1-aryl-3,3-dimethylpyrrolidin-2-carbonitriles in a convenient and environmentally benign way.
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