During the synthesis of the derivatives of styryl ketonic Mannich bases, a side -product IM,other than the normal Mannich base MA, is obtained. Mannich reaction is further studied and the formation mechanism of produc...During the synthesis of the derivatives of styryl ketonic Mannich bases, a side -product IM,other than the normal Mannich base MA, is obtained. Mannich reaction is further studied and the formation mechanism of product IM is postulated and discussed on the basis of deuterium labelling.展开更多
A convenient route for the conversion of inosine to the corresponding 6-amino, 6-methoxy and 6-ethoxy derivatives is reported. This conversion can be achieved by ammoniation or etherification of the 6-pyridinium inter...A convenient route for the conversion of inosine to the corresponding 6-amino, 6-methoxy and 6-ethoxy derivatives is reported. This conversion can be achieved by ammoniation or etherification of the 6-pyridinium intermediate(3) which can be readily produced under mild reaction conditions. The chemistry and characterization of these compounds are presented, A plausible mechanism of the reaction is proposed.展开更多
Thirteen α-methylene aromatic araminenone and four α-methylene aromatic aminoketones were prepared by modified Mannich reaction. On the basis of isotopic labeling, a plausible way of cleavage was proposed for the fo...Thirteen α-methylene aromatic araminenone and four α-methylene aromatic aminoketones were prepared by modified Mannich reaction. On the basis of isotopic labeling, a plausible way of cleavage was proposed for the formation of the M^＋- 17 fragment peak in the MS of the α-methylene aromatic araminenone and aminoketones. The characteristic chemical shift of the olefinic protons in ^1H NMR is also discussed.展开更多
o-Carboxybenzaldehyde (1)and acetone gave the Claisen-Schmidt condensation product, which readily cyclizes on acidification to give 1-oxo-3-acetonyl-dihydrobenzo [c]furan(4)in 68% yield. Other methyl ketones behaved s...o-Carboxybenzaldehyde (1)and acetone gave the Claisen-Schmidt condensation product, which readily cyclizes on acidification to give 1-oxo-3-acetonyl-dihydrobenzo [c]furan(4)in 68% yield. Other methyl ketones behaved similarly.展开更多
Fourteen substituted α-phenylcinnamic acids were prepared by the classical Perkin condensation. A plausible way of cleavage was involved in the formation of the specific fragment peaks in the MS of the α-phenylcinn...Fourteen substituted α-phenylcinnamic acids were prepared by the classical Perkin condensation. A plausible way of cleavage was involved in the formation of the specific fragment peaks in the MS of the α-phenylcinnamic acids . The characteristic chemical shift of the olefinic proton in HNMR is also discussed展开更多
Chrysanthemol, an active antiinflammatory sesquiterpene from Chrysanthemum indicum L., was synthesized in ten steps from R-(+)-carvone with an overall yield of 2.4%. The analytic data of the synthetic target compound ...Chrysanthemol, an active antiinflammatory sesquiterpene from Chrysanthemum indicum L., was synthesized in ten steps from R-(+)-carvone with an overall yield of 2.4%. The analytic data of the synthetic target compound was identical with that of natural chrysanthemol.展开更多
基金the National Natural Science Foundation of China.
文摘During the synthesis of the derivatives of styryl ketonic Mannich bases, a side -product IM,other than the normal Mannich base MA, is obtained. Mannich reaction is further studied and the formation mechanism of product IM is postulated and discussed on the basis of deuterium labelling.
文摘A convenient route for the conversion of inosine to the corresponding 6-amino, 6-methoxy and 6-ethoxy derivatives is reported. This conversion can be achieved by ammoniation or etherification of the 6-pyridinium intermediate(3) which can be readily produced under mild reaction conditions. The chemistry and characterization of these compounds are presented, A plausible mechanism of the reaction is proposed.
基金supported by the National Natural Science Foundation of China(No.39970867).
文摘Thirteen α-methylene aromatic araminenone and four α-methylene aromatic aminoketones were prepared by modified Mannich reaction. On the basis of isotopic labeling, a plausible way of cleavage was proposed for the formation of the M^＋- 17 fragment peak in the MS of the α-methylene aromatic araminenone and aminoketones. The characteristic chemical shift of the olefinic protons in ^1H NMR is also discussed.
文摘o-Carboxybenzaldehyde (1)and acetone gave the Claisen-Schmidt condensation product, which readily cyclizes on acidification to give 1-oxo-3-acetonyl-dihydrobenzo [c]furan(4)in 68% yield. Other methyl ketones behaved similarly.
文摘Fourteen substituted α-phenylcinnamic acids were prepared by the classical Perkin condensation. A plausible way of cleavage was involved in the formation of the specific fragment peaks in the MS of the α-phenylcinnamic acids . The characteristic chemical shift of the olefinic proton in HNMR is also discussed
文摘Chrysanthemol, an active antiinflammatory sesquiterpene from Chrysanthemum indicum L., was synthesized in ten steps from R-(+)-carvone with an overall yield of 2.4%. The analytic data of the synthetic target compound was identical with that of natural chrysanthemol.
