Syntheses, Asymmetric Syntheses Of 1,5-Benzothiazepion-α, α-Dimethyl-β-Lactam Derivatives

1,5-benzothiazepion is a kind of compound which has important physiological activities.Their syntheses,structures and pharmacological activities have attracted wide attention The C=N double bond in the molecules is one of the major parts where chemical reactions occurred.Thus a series of new 1,5-benzothiazepion derivatives have been synthesized and developed.In this paper,we use esters and 1,5-benzithiazepions as reacting substances.The lithium salt of ester enloates react with the 1,5-benzithiazepions ,and a series of new P -lactam derivatives of 1,5-benzothiazepion were abtained.Their stereochemistry and spectrum were analysised. Reaction mechanisms and rutions were discussed.The main research work are as follows:一. Iso-butyric acid react with ethanol , iso-propanol and menthol to synthesize three esters: ethyl isobutyrate,isopropyl isobutyrate and menthyl isobutyrate.二. Under -78℃+ ,esters react with LDA in THF to produce ester enolates.Then the ester enolates undergo cycloaddition reactions with l,5-benzothiazepions,and 2,4-disubstituted-l,5-benthiazepion- a , a -dimethyl- P -lactams are obtained.The products were determined by elemental analysis^ MS* 'HNMR, IR and X-ray single crystal diffraction.A new chiral substance(menthyl iosbutyrate)was used in the asymmetric syntheses of P -lactam derivatives of 1,5-benzothiazepion.We analysized the optical yields.For the first time,we tried to seperate the products by chiral column chromatography. We analysised > compaired the chiral substances that have been used in our laboratory.三. We found out and analysised the effect of the reacting substances to the reaction. The optimum condition was discussed,too4四. All of the new compounds were analysised by elemental analysis ,MS, ]HNMR and IR.Their spectra characters have also been studied.五. The products' stereostructures were analysised .Their conformations were discussed.六. We analysised reaction machanism of the cycloaddition reactions.