NMR Studies on Epoxidations of Allenamides. Evidence for Formation of Nitrogen-Substituted Allene Oxide and Spiro-Epoxide via Trapping Experiments
作者:C. Rameshkumar、Hui Xiong、Michael R. Tracey、Craig R. Berry、Letitia J. Yao、Richard P. Hsung
DOI:10.1021/jo011048d
日期:2002.2.1
the predominant formation of the 3-oxetanone, in the presence of furan, [4 + 3] cycloaddition of the nitrogen-substituted allene oxide or oxyallyl cation with furan occurs faster than the second epoxidation efficiently leading to cycloadducts. This rate difference plays an invaluable role for the success of a stereoselective sequential epoxidation-[4 + 3] cycloaddition reaction via DMDO epoxidations