Polysubstituted cyclopropane was easily constructed from p hydroxyl benzopropene type compounds when catalytic amount PdCl 2 was used. In this paper 1 methyl 2 ethyl 3,3 di(3,5 dimethoxyl 4 hydroxyl)benzocyclopr...Polysubstituted cyclopropane was easily constructed from p hydroxyl benzopropene type compounds when catalytic amount PdCl 2 was used. In this paper 1 methyl 2 ethyl 3,3 di(3,5 dimethoxyl 4 hydroxyl)benzocyclopropane and 1 methyl 2 ethyl 3,3 di(3,5 dihydroxyl 4 methoxyl)benzocyclopropane were first synthesized.展开更多
α-Hydroxy ketones are frequently involved in biologically important compounds and,therefore,the determination of the stereochemistry of these structural elements has attracted the attention in natural products chemis...α-Hydroxy ketones are frequently involved in biologically important compounds and,therefore,the determination of the stereochemistry of these structural elements has attracted the attention in natural products chemistry.In this paper a simpler Mosher′s method was developed from the modified Mosher′s method.It only need one configuration of MTPA to determine the absolute configurations of four α-hydroxy ketones with their（S）-and（R）-MTPA esters using（）1H NMR.The signals of protons on the same side with phenyl ring will be in the higher field than those of on the different side ones.Consequently according to the model the main configuration of compounds 1,2,3 and 4 were determined as S,R,R and S, respectively.展开更多
A C1-C7 fragment of the HIV-active Didemnaketal A analogue was synthesized from (R)-pulegone through 12 steps. Two new chiral centers, C3, C4 were successfully constructed by the steric induction in this approach and ...A C1-C7 fragment of the HIV-active Didemnaketal A analogue was synthesized from (R)-pulegone through 12 steps. Two new chiral centers, C3, C4 were successfully constructed by the steric induction in this approach and the aldehyde was selectively reduced.展开更多
文摘Polysubstituted cyclopropane was easily constructed from p hydroxyl benzopropene type compounds when catalytic amount PdCl 2 was used. In this paper 1 methyl 2 ethyl 3,3 di(3,5 dimethoxyl 4 hydroxyl)benzocyclopropane and 1 methyl 2 ethyl 3,3 di(3,5 dihydroxyl 4 methoxyl)benzocyclopropane were first synthesized.
文摘α-Hydroxy ketones are frequently involved in biologically important compounds and,therefore,the determination of the stereochemistry of these structural elements has attracted the attention in natural products chemistry.In this paper a simpler Mosher′s method was developed from the modified Mosher′s method.It only need one configuration of MTPA to determine the absolute configurations of four α-hydroxy ketones with their（S）-and（R）-MTPA esters using（）1H NMR.The signals of protons on the same side with phenyl ring will be in the higher field than those of on the different side ones.Consequently according to the model the main configuration of compounds 1,2,3 and 4 were determined as S,R,R and S, respectively.
文摘A C1-C7 fragment of the HIV-active Didemnaketal A analogue was synthesized from (R)-pulegone through 12 steps. Two new chiral centers, C3, C4 were successfully constructed by the steric induction in this approach and the aldehyde was selectively reduced.
