title: Efficient oxidation of oleanolic acid derivatives using magnesium bis(monoperoxyphthalate) hexahydrate (MMPP): A convenient 2-step procedure towards 12-oxo-28-carboxylic acid derivatives.
abstract: A new, straightforward and high yielding procedure to convert oleanolic acid derivatives into the corresponding δ-hydroxy-γ-lactones, by using the convenient oxidizing agent magnesium bis(monoperoxyphthalate) hexahydrate (MMPP) in refluxing acetonitrile, is reported. In addition, a two-step procedure for the preparation of oleanolic 12-oxo-28-carboxylic acid derivatives directly from Δ(12)-oleananes, without the need for an intermediary work-up, and keeping the same reaction solvent in both steps, is described as applied to the synthesis of 3,12-dioxoolean-28-oic acid.
authors.affiliation: Grupo de Química Farmacêutica, Faculdade de Farmácia da Universidade de Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra, Portugal.
authors.forename: Jorge A R
authors.initials: JA
authors.lastname: Salvador
authors.forename: Vânia M
authors.initials: VM
authors.lastname: Moreira
authors.forename: Rui M A
authors.initials: RM
authors.lastname: Pinto
authors.forename: Ana S
authors.initials: AS
authors.lastname: Leal
authors.forename: José A
authors.initials: JA
authors.lastname: Paixão