The reaction between 2,5-Dimethylpyrrole (1) and R_FI (2)(R_F: a, Cl(CF_2)_4; b, Cl(CF_2)_6; c, Cl(CF_2)_8; d, n-C_6F_(13); e, n-C_8F_(17)) in the presence of Na_2S_2O_4-NaHCO_3 in acetonitrile resulted in the formati...The reaction between 2,5-Dimethylpyrrole (1) and R_FI (2)(R_F: a, Cl(CF_2)_4; b, Cl(CF_2)_6; c, Cl(CF_2)_8; d, n-C_6F_(13); e, n-C_8F_(17)) in the presence of Na_2S_2O_4-NaHCO_3 in acetonitrile resulted in the formation of 2-perfluoroalkyl-2,5-dimethyl-2H-pyrrole (3) as a major product in good yield.展开更多
Isobutyraldehyde was used as starting material via three steps: oxidation, chlorination and dehydro-chlorination to yield methacrylic acid. The total yield of methacrylic acid is 49.7%.
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
Benzylsulfonamide was used as a source of nitrogen in the syn- thesis of azacrown ethers,and the cyclic intermediates were easily deben- zylsulfonylated by treating with CaF_2/H_2SO_4 to afford the azacrown ethers.
Heteroatom-directed aromatic lithiation reactions used for the regiospecific synthesis of o-isopropyl substituted phenolic and benzyl alcoholic compounds are described.
A new speech synthesis algorithm based on the LMA filter in Chinese text-to-speech systern is introduced. Using this method, the system can not only generate speech with higher quality, but also have a more powerful ...A new speech synthesis algorithm based on the LMA filter in Chinese text-to-speech systern is introduced. Using this method, the system can not only generate speech with higher quality, but also have a more powerful ability to modify the prosodic parameters, which ensures a far more natural and intelligible synthesized speech than ever before. First, the fundamental principles of the LMA filter and the construction of the synthesizer are presented, then, how to modify the acoustic parameters with this synthesizer is described; finally, the quantitative evaluation of the system's performance is shown while compared with a relatively successful PSOLA synthesizer KDTALK_1展开更多
文摘The reaction between 2,5-Dimethylpyrrole (1) and R_FI (2)(R_F: a, Cl(CF_2)_4; b, Cl(CF_2)_6; c, Cl(CF_2)_8; d, n-C_6F_(13); e, n-C_8F_(17)) in the presence of Na_2S_2O_4-NaHCO_3 in acetonitrile resulted in the formation of 2-perfluoroalkyl-2,5-dimethyl-2H-pyrrole (3) as a major product in good yield.
文摘Isobutyraldehyde was used as starting material via three steps: oxidation, chlorination and dehydro-chlorination to yield methacrylic acid. The total yield of methacrylic acid is 49.7%.
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Benzylsulfonamide was used as a source of nitrogen in the syn- thesis of azacrown ethers,and the cyclic intermediates were easily deben- zylsulfonylated by treating with CaF_2/H_2SO_4 to afford the azacrown ethers.
文摘Heteroatom-directed aromatic lithiation reactions used for the regiospecific synthesis of o-isopropyl substituted phenolic and benzyl alcoholic compounds are described.
文摘A new speech synthesis algorithm based on the LMA filter in Chinese text-to-speech systern is introduced. Using this method, the system can not only generate speech with higher quality, but also have a more powerful ability to modify the prosodic parameters, which ensures a far more natural and intelligible synthesized speech than ever before. First, the fundamental principles of the LMA filter and the construction of the synthesizer are presented, then, how to modify the acoustic parameters with this synthesizer is described; finally, the quantitative evaluation of the system's performance is shown while compared with a relatively successful PSOLA synthesizer KDTALK_1
