Study On The Synthesis Of1,3-oxazacyclo-Hexane Skeleton In Natural Products

The compounds containing1,3-oxazacyclohexane skeleton exhibit valuablebiological activities which receives significant effect in anticancer, sterilize, weedingand inhibition of lipase release. Since1995, more and more methods for the synthesisof2-aryl-5,6-dihydro-4H-1,3-oxazine were deseribed, but a few researches on thesyntheis of2-aryl-1,3-oxazines were reported. The following works on building of1,3-oxazayclohexane skeleton have been finished in this thesis.1. The synthetic methods of1,3-oxazacyclohexane in recent years are reviewed,and the researches and means about this thesis are brought forward.2. Pyrrole-2-aldehyde was synthesized from pyrrole and DMF in the presence ofphosphorus oxychloride. The corresponding aromatic oxime was synthesized from thereaction between aromatic aldehyde and hydroxylamine hydrochloride in water. Thenaromatic oxime refluxed in acetic anhydride, aromatic nitrile was synthesized.3. L-Homoserine was synthesized with L-methionine and iodomethane as thestarting material in the NaHCO₃aqueous solution. Through hydroxyl protection andamino protection, O-TBS-L-Homoserine, N-Boc-L-Homoserine and O-TBS-N-Boc-L-Homoserine were synthesized. The methyl-N-Boc-L-Homoserinate was synthesizedfrom N-Boc-L-Homoserine and iodomethane. And then the1,3-oxazacyclohexane wassynthesized from the reaction between pyrrole-2-aldehyde （pyrrole-2-carbonitrile） andmethyl L-Homoserinate.4. The1,3-oxazacyclohexane was synthesized with pyrrole-2-carbonitrile and1,3-butanediol as the starting material, respectively under sulfuric acid, PPTS andMontmorillonite K-10as catalyst.5. The1,3-oxazacyclohexane was synthesized from the reaction between aromaticaldehyde and3-amino-1-propanol in the KI/I₂atmosphere. 6. The1,3-oxazacyclohexanes were synthesized with aromatic nitrile and3-amino-1-propanol as the starting material, under solvent-free conditions and catalyzedby K-10montmorillonite clays at150℃.7. The structures of some intermediates and targets were confirmed by1H NMRand13C NMR analysises.