Electrochemical-ESR technique (ex situ method) with spin traps phenyl tert-butyl nitrone (PBN) and 5,5-dimethyl-1-Pyrroline-1-oxide (DMPO) has been applied to the detection of radical intermediates produced during ele...Electrochemical-ESR technique (ex situ method) with spin traps phenyl tert-butyl nitrone (PBN) and 5,5-dimethyl-1-Pyrroline-1-oxide (DMPO) has been applied to the detection of radical intermediates produced during electroreduction of propargyl alcohol (PA) at platinized platinum electrode in an acidified alcohol-aqua solution. Propargyl radical and H have been detected by PBN and DMPO, respectively. As a result of the discovery of these radicals, an evidence for a radical mechanism of the electroreduction of PA put forward by some authors might be obtained beyond all doubt.展开更多
The S (+) sulcatol(1) was prepared in 4 steps. Sodium phenyl sulfinate was reacted with bromoacetone in ethanol to give 1 phenylsulfonyl 2 propanone(2). Alkylation of (2) by 1 chloro 3 methyl 2 butene(3) in the presen...The S (+) sulcatol(1) was prepared in 4 steps. Sodium phenyl sulfinate was reacted with bromoacetone in ethanol to give 1 phenylsulfonyl 2 propanone(2). Alkylation of (2) by 1 chloro 3 methyl 2 butene(3) in the presence of K 2CO 3 through solid liquid PTC in DMF at 40～50 ℃ gave 3 phenylsulfonyl 6 methyl 5 heptene 2 one(4). The sulfone moiety of (4) was removed by Raney Ni reduction under mild conditions and the key intermediate prochiral 6 methyl 5 heptene 2 one(5) was obtained. Sulcatol(1) with optical purity of 94%e.e. was obtained by Baker′s yeast mediated reduction of (5).展开更多
The similarities of The mass spectra of any two isomers (n and m) are represented by a similarity index [SI(n, m)]. The similarity index is calculated using a novel formula: SI(n, m) ={min[R(n, i), R(m, i)] / max[R(n,...The similarities of The mass spectra of any two isomers (n and m) are represented by a similarity index [SI(n, m)]. The similarity index is calculated using a novel formula: SI(n, m) ={min[R(n, i), R(m, i)] / max[R(n, j), R(m, i)]} 100 Where R(n, j) and R(m, j) are The intensity ratio of a fragment pair (j); j is an ordinal number which is arbitrarily assigned to a selected pair of fragments. The value of similarity index ranges from 0 to 100, when n = m, The SI(n, m) = 100. Similarity indices of mass spectra of isomeric tetradecadien-1-ols were calculated by The "min.-max." Fuzzy similarity analysis. The universality of The method was confirmed by The testing with mass spectra of ten isomers of tetradecadien-1-ols.展开更多
文摘Electrochemical-ESR technique (ex situ method) with spin traps phenyl tert-butyl nitrone (PBN) and 5,5-dimethyl-1-Pyrroline-1-oxide (DMPO) has been applied to the detection of radical intermediates produced during electroreduction of propargyl alcohol (PA) at platinized platinum electrode in an acidified alcohol-aqua solution. Propargyl radical and H have been detected by PBN and DMPO, respectively. As a result of the discovery of these radicals, an evidence for a radical mechanism of the electroreduction of PA put forward by some authors might be obtained beyond all doubt.
文摘The S (+) sulcatol(1) was prepared in 4 steps. Sodium phenyl sulfinate was reacted with bromoacetone in ethanol to give 1 phenylsulfonyl 2 propanone(2). Alkylation of (2) by 1 chloro 3 methyl 2 butene(3) in the presence of K 2CO 3 through solid liquid PTC in DMF at 40～50 ℃ gave 3 phenylsulfonyl 6 methyl 5 heptene 2 one(4). The sulfone moiety of (4) was removed by Raney Ni reduction under mild conditions and the key intermediate prochiral 6 methyl 5 heptene 2 one(5) was obtained. Sulcatol(1) with optical purity of 94%e.e. was obtained by Baker′s yeast mediated reduction of (5).
文摘The similarities of The mass spectra of any two isomers (n and m) are represented by a similarity index [SI(n, m)]. The similarity index is calculated using a novel formula: SI(n, m) ={min[R(n, i), R(m, i)] / max[R(n, j), R(m, i)]} 100 Where R(n, j) and R(m, j) are The intensity ratio of a fragment pair (j); j is an ordinal number which is arbitrarily assigned to a selected pair of fragments. The value of similarity index ranges from 0 to 100, when n = m, The SI(n, m) = 100. Similarity indices of mass spectra of isomeric tetradecadien-1-ols were calculated by The "min.-max." Fuzzy similarity analysis. The universality of The method was confirmed by The testing with mass spectra of ten isomers of tetradecadien-1-ols.
