ISSN:
1573-9171
Keywords:
β-cyclohexylpropenals and α-cycloalkylidenalkanals
;
Knoevenagel condensation
;
α,β∶γ,δ-dienones
;
2H-pyrans
;
valence isomerization
;
effect of γ-substituents
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract β-Cyclohexylacrolein, β-cyclohexylmethacrolein, or α-cycloalkylidenalkanals were condensed with methyl acetoacetate or dimethyl malonate to give the δ-cyclohexyl- and δ,δ-alkylene-substituted α,α-dicarbonyl-containing α,β∶γ,δ-dienes. The structures of the reaction products were studied using1H NMR,13C NMR, and UV spectroscopy. The diene keto esters bearing no substituents at the γ-position were shown to be in fact three-component equilibrium mixtures comprised ofE- andZ-isomers of the diene (at the α,β bond) and a corresponding 2H-pyran. On the other hand, for keto esters with a Me group at the γ-position the equilibrium is shifted entirely to the 2H-pyrans. In contrast with the keto esters, dienic diesters exist only in the open form.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00696716
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