Wei Cui, Zhou Zhou, Pang Guang-Li, Liang Cui, Mo Dong-Liang
State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, 15 Yu Cai Road, Guilin 541004, China.
Org Lett. 2022 Jun 17;24(23):4104-4108. doi: 10.1021/acs.orglett.2c01049. Epub 2022 Jun 6.
A variety of oxazabicyclo[4.2.1]nonanone derivatives were prepared in good yields through a cinchonidine-catalyzed cascade reaction of -aryl-α,β-unsaturated nitrones and 1-ethynylnaphthalen-2-ols. Mechanistic studies show that the reaction undergoes a [4 + 3] cycloaddition of nitrones to vinylidene -quinone methide generated in situ from 1-ethynylnaphthalen-2-ols in the presence of cinchonidine, 1,3-rearrangement of N-O vinyl moieties, ring-opening, and finally double intramolecular cyclizations to afford oxazabicyclo[4.2.1]nonanones over five steps in a one-pot reaction.
