Enantioselective construction of the tricyclic core of curcusones A–D via a cross-electrophile coupling approach

Herein we report our recent progress toward the enantioselective total synthesis of the diterpenoid natural products curcusones A–D by means of complementary Stetter annulation or ring-closing metathesis (RCM) disconnections. Using the latter approach, we have achieved the concise construction of the 5–7–6 carbocyclic core embedded in each member of the curcusone family. Essential to this route is the use of a cross-electrophile coupling strategy, which has not previously been harnessed in the context of natural product synthesis

A Small-scale Procedure for Acid-catalyzed Ketal Formation

A modified procedure for dehydrative ketal protections is disclosed, which serves as an alternative to the classic Dean–Stark protocol. Studies show that this new procedure can outperform the Dean–Stark apparatus on small scales and thus serves as a complementary approach to effect dehydrative ketalizations. A detailed procedure for this apparatus is presented

Progress toward the Enantioselective Synthesis of Curcusones A–D via a Divinylcyclopropane Rearrangement Strategy

We report our iterative efforts toward the divergent total syntheses of curcusones A–D via Suzuki coupling, intramolecular cyclopropanation, and a key divinylcyclopropane rearrangement. Progress of our synthesis was repeatedly challenged by the highly substrate-dependent cyclopropanation step, which we could ultimately overcome by judicious choice of substituents on the six-membered ring fragment

Synthesis of Aryl Ketoamides via Aryne Insertion into Imides

An insertion of arenes into both imides and anhydrides via reactive aryne intermediates is presented. The reaction is performed under exceptionally mild conditions, and the corresponding ketoamide products are amenable to derivatization to deliver a variety of synthetically useful motifs such as quinolones, indoles, and ketoanilines

Enantioselective construction of the tricyclic core of curcusones A–D via a cross-electrophile coupling approach

Herein we report our recent progress toward the enantioselective total synthesis of the diterpenoid natural products curcusones A–D by means of complementary Stetter annulation or ring-closing metathesis (RCM) disconnections. Using the latter approach, we have achieved the concise construction of the 5–7–6 carbocyclic core embedded in each member of the curcusone family. Essential to this route is the use of a cross-electrophile coupling strategy, which has not previously been harnessed in the context of natural product synthesis

Discussion Addendum for: The Direct Acyl-Alkylation of Arynes. Preparation of Methyl 2-(2-acetylphenyl)acetate

For the past 50 years, benzynes and related arynes have been a major subject of study among physical organic chemists due to their unusual electronic and structural properties. However, the utility of these strained intermediates in the domain of chemical synthesis has only relatively recently undergone a vibrant expansion. The direct insertion of aryne and heteroaryne moieties into carbon-carbon and carbon-heteroatom σ bonds presents an intriguing and unique strategy for the rapid functionalization of aryl and heteroaryl systems. Following our 2009 Organic Syntheses article on the acyl-alkylation of arynes with β-ketoesters, there have been numerous reports of related transformations involving these highly reactive intermediates. This discussion addendum is intended to document advances made in the field of (hetero)arynes since our initial disclosure. Topics covered will be divided as follows: recent methods for the acyl-functionalization of arynes, syntheses of related strained systems, applications in heterocycle synthesis, miscellaneous transformations, and strategic uses in natural product synthesis. A supplemental review on aryne insertions into σ bonds is available. Applications of arynes in transition metal catalysis will not be discussed in detail, however there are thorough reviews on the subject

Stereospecific Overman Rearrangement of Substituted Cyclic Vinyl Bromides: Access to Fully Substituted α-Amino Ketones

A versatile thermal Overman rearrangement of enantioenriched, cyclic allylic alcohols providing tertiary allylic amines has been developed. The vinyl bromide used to control enantioselectivity in a preceding CBS reduction is utilized as a synthetic handle for the preparation of tertiary α-amino ketones and related derivatives in an asymmetric fashion

Stereospecific Overman Rearrangement of Substituted Cyclic Vinyl Bromides: Access to Fully Substituted α-Amino Ketones

A versatile thermal Overman rearrangement of enantioenriched, cyclic allylic alcohols providing tertiary allylic amines has been developed. The vinyl bromide used to control enantioselectivity in a preceding CBS reduction is utilized as a synthetic handle for the preparation of tertiary α-amino ketones and related derivatives in an asymmetric fashion

The foodborne transmission of Hepatitis E virus to humans

This is the final version. Available on open access from Springer via the DOI in this recordData Availability: All data are obtained from publicly available information.Globally, Hepatitis E virus (HEV) causes over 20 million cases worldwide. HEV is an emerging and endemic pathogen within economically developed countries, chiefly resulting from infections with genotype 3 (G3) HEV. G3 HEV is known to be a zoonotic pathogen, with a broad host range. The primary source of HEV within more economically developed countries is considered to be pigs, and consumption of pork products is a significant risk factor and known transmission route for the virus to humans. However, other foods have also been implicated in the transmission of HEV to humans. This review consolidates the information available regarding transmission of HEV and looks to identify gaps where further research is required to better understand how HEV is transmitted to humans through food.CefasSeedcornUniversity of ExeterWellcome TrustRoyal Societ