Preparation of 3-hydroxyoxindoles with dimethyldioxirane and their use for the synthesis of natural products. Oscar R. Suárez-Castillo, Maricruz Sánchez-Zavala, Myriam Meléndez-Rodríguez, Luis E. Castelán-Duarte, Martha S. Morales-Ríos, Pedro Joseph-Natha. http://dx.doi.org/10.1016/j.tet.2006.01.036
This work describes a general protocol for the oxidation of indole and oxindole derivatives with dimethyldioxirane to give 3-hydroxyoxindoles present in many natural products. This strategy allowed us to synthesize the natural product 1, to carry out the first total synthesis of 4, a formal total synthesis of donaxaridine (5) and to achieve the synthesis of pyrroloindoline 8, a debromo analogue of the natural product flustraminol B (7).