1,3-dipolar cycloaddition reactions of nitrile oxides with 4,5-dihydrooxazole and 4,5-dihydrothiazole derivatives
作者:David J. Miller、Richard M. Scrowston、Peter D. Kennewell、Robert Westwood
DOI:10.1016/s0040-4020(01)90381-3
日期:1992.9
4,5-Dihydro-2-metyloxazole 1a and 4,5-dihydro-2,4,4-trimethyloxazole 1b, which are examples of cyclic imidate esters, undergo 1,3-dipolar cycloaddition reactions with benzonitrile N-oxide, to give the appropriate 5,6-dihydro-7a-methyl-3-phenyl-7aH-oxazolo[3,2-d]-1,2,4-oxadiazole (2a and 2b respectively). 4,5-Dihydro-2-methylthiazole 1c gives the thia analogue 2c.
作为环状亚氨酸酯的实例的4,5-二氢-2-间甲基恶唑1a和4,5-二氢-2,4,4-三甲基恶唑1b与苄腈N-氧化物进行1,3-偶极环加成反应,得到适当的5,6-二氢-7a-甲基-3-苯基-7a H-恶唑并[3,2 - d ] -1,2,4-恶二唑(分别为2a和2b)。4,5-二氢-2-甲基噻唑1c给出硫杂类似物2c。