Preparation of α-substituted acroleins via the reaction of aldehyde with dihalomethane and diethylamine
作者:Yung-Son Hon、Feng-Jon Chang、Ling Lu
DOI:10.1039/c39940002041
日期:——
Treatment of ozonides or aldehydes with a mixture of dihalomethane and diethylamine in dichloromethane affords α-substituted acroleins in good yields, the β-carbon of the acrolein being derived from dihalomethane; the relative rates and yields are in the following order: CH2l2 > CH2Br2 > CH2Cl2.
The structures of 1,2,4-trioxolanes (ozonides) (2a-2f) derived from mono-substituted alkenes (1a-1f), respectively, were determined by spectroscopic methods, such as H-1-nmr, C-13-nmr, ir, two-dimensional nmr, and mass spectra. The coupling constant of the geminal protons on the trioxolane ring is zero. This unusual coupling constant resulted from the electronegativity of two oxygen atoms near the geminal protons.