The novel 19 nor l α ,25 dihydroxy vitamin D 3 analogues possessing an ethyl at the 2 position(4 and 5), were synthesized by coupling 25 hydroxy Windaus Grundmann ketone derivative 20 with A ring syntho...The novel 19 nor l α ,25 dihydroxy vitamin D 3 analogues possessing an ethyl at the 2 position(4 and 5), were synthesized by coupling 25 hydroxy Windaus Grundmann ketone derivative 20 with A ring synthons(15 and 19) respectively. The enantioselective synthesis of substituted bicyclic hexanes structure A ring synthons, started from all cis 3,5 dihydroxy 4 ethyl 1 (methoxycarbonyl)cyclohexane via lipase catalyzd asymmetrization, was demonstrated.展开更多
Hexaalkylguanidinium halides exhibit an efficient catalytic activity in the synthesis of cyclic carbonates from epoxides and carbon dioxide. By this method cyclic carbonates can be obtained in a high yield and a high ...Hexaalkylguanidinium halides exhibit an efficient catalytic activity in the synthesis of cyclic carbonates from epoxides and carbon dioxide. By this method cyclic carbonates can be obtained in a high yield and a high selectivity at a low temperature and atmospheric pressure. This procedure is easy for the product isolation and recycling of the catalyst.展开更多
First cationic 6-quinolyl substituted dithiaporphyrin was synthesized using Skraup quinoline methodology from thiaporphyrin bearing 4-acetamidophenyl prepared by condensation reaction of aromatic aldehyde with pyrrole.
文摘The novel 19 nor l α ,25 dihydroxy vitamin D 3 analogues possessing an ethyl at the 2 position(4 and 5), were synthesized by coupling 25 hydroxy Windaus Grundmann ketone derivative 20 with A ring synthons(15 and 19) respectively. The enantioselective synthesis of substituted bicyclic hexanes structure A ring synthons, started from all cis 3,5 dihydroxy 4 ethyl 1 (methoxycarbonyl)cyclohexane via lipase catalyzd asymmetrization, was demonstrated.
文摘Hexaalkylguanidinium halides exhibit an efficient catalytic activity in the synthesis of cyclic carbonates from epoxides and carbon dioxide. By this method cyclic carbonates can be obtained in a high yield and a high selectivity at a low temperature and atmospheric pressure. This procedure is easy for the product isolation and recycling of the catalyst.
文摘First cationic 6-quinolyl substituted dithiaporphyrin was synthesized using Skraup quinoline methodology from thiaporphyrin bearing 4-acetamidophenyl prepared by condensation reaction of aromatic aldehyde with pyrrole.
