Towards the Total Synthesis of Mycaperoxide B: Probing Biosynthetic Rationale

Stereodivergent Total Syntheses of (+)-Mycaperoxides C, D, G Methyl Ester and (-)-Mycaperoxide B

Mycaperoxides are natural endoperoxides isolated from different Mycale genus sponges, showing significant antiviral or antibacterial activities. We report herein the first total syntheses of representative congeners of this family from sclareol using a stereodivergent approach. Thus, an innovative oxidative ring expansion of cyclobutanol was used to bring the 1,2-dioxane subunit, and a Mukaiyama aldol reaction on peroxycarbenium species was utilized to install the propionic acid subunit. During the study toward (+)-mycaperoxide D methyl ester (2), the isolation of the eight possible diastereomers under their ethyl thioester form allowed to build a pertinent database for further NMR assignment studies. Thus, we completed the total syntheses of (+)-mycaperoxides D, C, G methyl ester, and (-)-mycaperoxide B in 11 to 15 steps, confirming their original assignment.

Cobalt-Catalyzed Oxygenation/Dearomatization of Furans

The dearomatization of aromatic compounds using cobalt(II) acetylacetonate with triplet oxygen and triethylsilane converts furans, benzofurans, pyrroles, and thiophenes to a variety of products, including lactones, silyl peroxides, and ketones.

Peroxides with Anthelmintic, Antiprotozoal, Fungicidal and Antiviral Bioactivity: Properties, Synthesis and Reactions

The biological activity of organic peroxides is usually associated with the antimalarial properties of artemisinin and its derivatives. However, the analysis of published data indicates that organic peroxides exhibit a variety of biological activity, which is still being given insufficient attention. In the present review, we deal with natural, semi-synthetic and synthetic peroxides exhibiting anthelmintic, antiprotozoal, fungicidal, antiviral and other activities that have not been described in detail earlier. The review is mainly concerned with the development of methods for the synthesis of biologically active natural peroxides, as well as its isolation from natural sources and the modification of natural peroxides. In addition, much attention is paid to the substantially cheaper biologically active synthetic peroxides. The present review summarizes 217 publications mainly from 2000 onwards.

Structural diversity and chemical synthesis of peroxide and peroxide-derived polyketide metabolites from marine sponges

The structural elucidation, chemical synthesis and therapeutic potential of peroxide and peroxide-derived sponge metabolites, with special focus on their intriguing structural similarities and differences from a biogenetic perspective, are reviewed.

Relative and absolute stereochemistry of diacarperoxides: antimalarial norditerpene endoperoxides from marine sponge Diacarnus megaspinorhabdosa

Five new norditerpene endoperoxides, named diacarperoxides H-L (1-5), and a new norditerpene diol, called diacardiol B (6), were isolated from the South China Sea sponge, Diacarnus megaspinorhabdosa. Their structures, including conformations and absolute configurations, were determined by using spectroscopic analyses, computational approaches and chemical degradation. Diacarperoxides H-J (1-3) showed some interesting stereochemical issues, as well as antimalarial activity.

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.