- A convenient method for the preparation of N-substituted 1-acetonylaminocyclopropanes from acetoacetic ester ethylene acetal
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Reaction of 1-acetonyl-1-tosyloxycyclopropane with primary or secondary amines affords the corresponding 1-acetonyl-1-aminocyclopropanes in quantitative yields. The starting tosylate was prepared from acetoacetic ester ethylene acetal in three steps through its cyclopropanation with ethylmagnesium bromide in the presence of 0.2 equivalent of titanium (IV) isopropoxide, followed by deprotection of the carbonyl group and tosylation.
- Raiman, Marina V.,Il'ina, Natalia A.,Kulinkovich, Oleg G.
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p. 1053 - 1054
(2007/10/03)
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- ETUDE DES PETITS CYCLES-XLIII. REACTIONS D'ADDITION SUR LES α-CYCLOPROPYLIDENE-CETONES ET SUR LES α-CYCLOPROPYLIDENE-ALDEHYDES
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α-Cyclopropylidene ketones and aldehydes show high reactivity towards 1,4-addition of methanol in acidic or basic medium, water and hydrochloric acid giving α-(1-methoxy cyclopropyl) ketones and aldehydes, α-(1-hydroxy cyclopropyl) ketones and α-(1-chloro cyclopropyl) ketones and aldehydes respectively.The reaction of α-cyclopropylidene-ketones with Grignard reagents gives mainly α-cyclopropyl ketones (the 1,4-addition product) besides α-cyclopropylidene carbinols (the 1,2-addition product).Addition of methyl-lithium and lithium dimethylcuprate lead to the expected 1,2- and 1,4-addition products,respectively.The comparison of the se results and those corresponding to α-isopropylidene-ketones confirms the higher tendency of α-cyclopropylidene-ketones to give 1,4-addition products; the measurement of polarographic reduction potentials confirms, in some cases, this difference.The reaction of HOBr (NBS, DMSO, H2O) with α-cyclopropylidene ketones produces α-hydroxy β-bromo ketones whereas the corresponding α-isopropylidene ketones give β-hydroxy α-bromo ketones.
- Lechevallier, A.,Huet, F.,Conia, J.M.
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p. 3317 - 3328
(2007/10/02)
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- ADDITION REACTIONS TO α-CYCLOPROPYLIDENE KETONES AND ALDEHYDES.
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α-Cyclopropylidene ketones show high reactivity towards 1,4-addition reactions.
- Huet, F.,Lechevallier, A.,Conia, J. M.
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p. 3585 - 3588
(2007/10/02)
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