Reduction of 2- and 4-acetoxymethyl derivatives of 5-tert-butylfuran-3-carboxylic acid leads to the corresponding bis(hydroxymethyl)furans. Bis(chloromethyl)furans prepared from the latter were involved in reaction with sodium diethyl phosphite. In the presence of two equivalents of a phosphorus-containing nucleophile, bis(phosphonomethyl)furans are formed. One equivalent of sodium diethyl phosphite reacts with 3,4-bis(chloromethyl)furan to give a mixture of 3-and 4-phosphorylated products in a 4.5:1 ratio in a low yield. The revealed difference in reactivity between the 3- and 4-chloromethyl groups demonstrates the importance of shielding of the chloromethyl group by the neighboring tert-butyl substituent. Examination of the H-1 NMR spectra of 3,4-bis(hydroxymethyl)-, 3,4-bis(chloromethyl)-, 3,4-bis(diethoxyphosphorylmethyl)5-tert-butylfurans, and also specially prepared 5-tert-butyl-3-(diethoxyphosphorylmethyl)-4-(ethoxymethyl)-2-methylfuran established that the signal of the substituent neighboring to the tert-butyl group is always shifted downfield.
Reduction of 2- and 4-acetoxymethyl derivatives of 5-tert-butylfuran-3-carboxylic acid leads to the corresponding bis(hydroxymethyl)furans. Bis(chloromethyl)furans prepared from the latter were involved in reaction with sodium diethyl phosphite. In the presence of two equivalents of a phosphorus-containing nucleophile, bis(phosphonomethyl)furans are formed. One equivalent of sodium diethyl phosphite reacts with 3,4-bis(chloromethyl)furan to give a mixture of 3-and 4-phosphorylated products in a 4.5:1 ratio in a low yield. The revealed difference in reactivity between the 3- and 4-chloromethyl groups demonstrates the importance of shielding of the chloromethyl group by the neighboring tert-butyl substituent. Examination of the H-1 NMR spectra of 3,4-bis(hydroxymethyl)-, 3,4-bis(chloromethyl)-, 3,4-bis(diethoxyphosphorylmethyl)5-tert-butylfurans, and also specially prepared 5-tert-butyl-3-(diethoxyphosphorylmethyl)-4-(ethoxymethyl)-2-methylfuran established that the signal of the substituent neighboring to the tert-butyl group is always shifted downfield.
Reaction of Furan-Based o-Quinodimethanes with Triplet Oxygen. Formation of Cyclic Peroxides,1
作者:Chin-Hsing Chou、Walter S. Trahanovsky
DOI:10.1021/jo00122a024
日期:1995.9
Formation of cyclic peroxides 2a, 2b, and 2c from the reactions of 2,3-dimethylene-2,3-dihydrofuran (1a) and the 5-methyl (1b) and 5-tert-butyl (1c) derivatives with triplet oxygen is reported. Thermolysis of cyclic peroxide 2c gives dialdehyde 5, hydroxy aldehydes 6 and 7, and diol 8 as products.
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作者:L. M. Pevzner
DOI:10.1023/a:1021605324604
日期:——
Reduction of 2- and 4-acetoxymethyl derivatives of 5-tert-butylfuran-3-carboxylic acid leads to the corresponding bis(hydroxymethyl)furans. Bis(chloromethyl)furans prepared from the latter were involved in reaction with sodium diethyl phosphite. In the presence of two equivalents of a phosphorus-containing nucleophile, bis(phosphonomethyl)furans are formed. One equivalent of sodium diethyl phosphite reacts with 3,4-bis(chloromethyl)furan to give a mixture of 3-and 4-phosphorylated products in a 4.5:1 ratio in a low yield. The revealed difference in reactivity between the 3- and 4-chloromethyl groups demonstrates the importance of shielding of the chloromethyl group by the neighboring tert-butyl substituent. Examination of the H-1 NMR spectra of 3,4-bis(hydroxymethyl)-, 3,4-bis(chloromethyl)-, 3,4-bis(diethoxyphosphorylmethyl)5-tert-butylfurans, and also specially prepared 5-tert-butyl-3-(diethoxyphosphorylmethyl)-4-(ethoxymethyl)-2-methylfuran established that the signal of the substituent neighboring to the tert-butyl group is always shifted downfield.