Diversity Synthesis Of 6-Membered-Ring Fused Oxazolidones

6-Membered-ring fused Oxazolidones play significant role in the total synthesis of natural products and drugs. Their structural skeleton can be used as key intermediate for the synthesis of a number of natural alkaloids. In this thesis, Aza-Prins cyclization reaction catalyzed by Lewis acid BF3?Et2O for synthesis of different substituted 6-membered-ring fused oxazolidones was discovered. The best reaction condition was found by optimizing the different reaction parameters. With the optimized reaction conditions, 22 different 6-membered-ring fused oxazolidones were synthesised. Based on experimental studies, a possible mechanism of the reaction was proposed. Density Functional Theory justified the failed cyclization for 8 examples. The products were obtained in good yields(yield up to 94%), very high regioselectivity and diastereo selectivity, the best regioselectivity appeared in 2, 3-carbon substituted 6-membered-ring fused oxazolidones, their dr values were more than 99/1.