A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)...A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)-3-[(1R)-tert-butyldimethylsilyloxyethyl]-4-acetoxy-2-azetidi-none(4AA)upon thionocarboxlic acid.The intermediates and the target product were characterized by 1HNMR,IR,elementary analysis and MS.展开更多
Mesoporous molecular sieves Al-MCM-41 with n（SiO2）/n（Al2O3） ratio being 20,50 and 100 were prepared.As proved by X-ray diffraction（XRD） patterns and the N2 physical sorption,the as-synthesized Al-MCM-41 exhibite...Mesoporous molecular sieves Al-MCM-41 with n（SiO2）/n（Al2O3） ratio being 20,50 and 100 were prepared.As proved by X-ray diffraction（XRD） patterns and the N2 physical sorption,the as-synthesized Al-MCM-41 exhibited typical hexagonal structure,large surface areas and narrow pore distribution.The performance of HAl-MCM-41 as catalyst for tert-butylation of p-cresol with methyl tert-butyl-ether（MTBE） was then investigated.The effects of temperature,weight hourly space velocity（WHSV） and the feed ratio n（MTBE）/n（p-cresol） on p-cresol conversion and product selectivity were examined.The results showed that mesoporous HAl-MCM-41 molecular sieves（n（SiO2）/n（Al2O3） = 20） is an efficient catalyst with high activity,selectivity and stability for the synthesis of 2-tert-butyl-p-cresol from p-cresol and MTBE by tert-butylation.展开更多
文摘A compound ethyl(5S,6R)-2-(4-methylphenyl)-6-[(1R)-tert-butyldimethylsilyloxyethy]-penem-3-carboxylate was synthesized through displacement,acylation and Wittig cyclization reaction of optically active material(3R,4R)-3-[(1R)-tert-butyldimethylsilyloxyethyl]-4-acetoxy-2-azetidi-none(4AA)upon thionocarboxlic acid.The intermediates and the target product were characterized by 1HNMR,IR,elementary analysis and MS.
文摘Mesoporous molecular sieves Al-MCM-41 with n（SiO2）/n（Al2O3） ratio being 20,50 and 100 were prepared.As proved by X-ray diffraction（XRD） patterns and the N2 physical sorption,the as-synthesized Al-MCM-41 exhibited typical hexagonal structure,large surface areas and narrow pore distribution.The performance of HAl-MCM-41 as catalyst for tert-butylation of p-cresol with methyl tert-butyl-ether（MTBE） was then investigated.The effects of temperature,weight hourly space velocity（WHSV） and the feed ratio n（MTBE）/n（p-cresol） on p-cresol conversion and product selectivity were examined.The results showed that mesoporous HAl-MCM-41 molecular sieves（n（SiO2）/n（Al2O3） = 20） is an efficient catalyst with high activity,selectivity and stability for the synthesis of 2-tert-butyl-p-cresol from p-cresol and MTBE by tert-butylation.
