Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products.

The present review describes the current status of synthetic five and six-membered cyclic peroxides such as 1,2-dioxolanes, 1,2,4-trioxolanes (ozonides), 1,2-dioxanes, 1,2-dioxenes, 1,2,4-trioxanes, and 1,2,4,5-tetraoxanes. The literature from 2000 onwards is surveyed to provide an update on synthesis of cyclic peroxides. The indicated period of time is, on the whole, characterized by the development of new efficient and scale-up methods for the preparation of these cyclic compounds. It was shown that cyclic peroxides remain unchanged throughout the course of a wide range of fundamental organic reactions. Due to these properties, the molecular structures can be greatly modified to give peroxide ring-retaining products. The chemistry of cyclic peroxides has attracted considerable attention, because these compounds are used in medicine for the design of antimalarial, antihelminthic, and antitumor agents.

Synthesis of asymmetric peroxides: transition metal (Cu, Fe, Mn, Co) catalyzed peroxidation of beta-dicarbonyl compounds with tert-butyl hydroperoxide.

The transition metal (Cu, Fe, Mn, Co) catalyzed peroxidation of beta-dicarbonyl compounds at the alpha position by tert-butyl hydroperoxide was discovered. A selective, experimentally convenient, and gram-scale method was developed for the synthesis of alpha-peroxidated derivatives of beta-diketones, beta-keto esters, and diethyl malonate. Virtually stoichiometric (2-3/1) molar ratios of tert-butyl hydroperoxide and a dicarbonyl compound were used in the reactions with beta-diketones and beta-keto esters. The target compounds were synthesized in the highest yields from beta-keto esters (45-90%) and in somewhat lower yields from beta-diketones (46-75%) and malonates (37-67%).

Facile and selective procedure for the synthesis of bridged 1,2,4,5-tetraoxanes; strong acids as cosolvents and catalysts for addition of hydrogen peroxide to beta-diketones.

A facile, experimentally simple, and selective method was developed for the synthesis of bridged 1,2,4,5-tetraoxanes based on the reaction of hydrogen peroxide with beta-diketones catalyzed by strong acids (H(2)SO(4), HClO(4), HBF(4), or BF(3)). The yields of the target products vary from 44% to 77%. 1,2,4,5-Tetraoxanes can easily be separated from other reaction products by column chromatography. A high concentration of a strong acid is a key factor determining the selectivity of formation and the yield of 1,2,4,5-tetraoxanes. Unlike many compounds containing the O-O bond, which undergo rearrangements in acidic media, the resulting cyclic peroxides are quite stable under these conditions.