David Gonzalez

Allylic azides are versatile structural motifs in organic synthesis because the proximal double bond enables a [3,3]‐sigmatropic rearrangement, named as the Winstein rearrangement. In this work, an experimental and theoretical study on the double Winstein rearrangement occurring in azidodienediols derived from the biocatalytic dihydroxylation of substituted benzylazides is presented. Substrates bearing a methyl group at the ortho or meta position produced exclusively rearranged exo‐diendiols with the azide group anti to the diol moiety as the major constituent. In the case of para methyl substrates, an equilibrium mixture of rearranged and non‐rearranged products was observed, indicating that a full conversion to the exo‐dienediols is not possible within this substitution pattern. On the other hand, the presence of a chloro substituent in the diene moiety completely precluded the Winstein rearrangement to take place, giving rise exclusively to the traditional cis‐cyclohexadienediols. The observed results were analyzed to determine the mechanistic and kinetic aspects and scope limitations of the reaction as a synthetic tool.

Chemicals that meet the criteria of a riot control agent as defined by the Chemical Weapons Convention (an international chemical disarmament and non-proliferation treaty) are reviewed by the Scientific Advisory Board of the Organisation for the Prohibition of Chemical Weapons.

This manuscript describes the enantioselective synthesis of the aminocyclitol moiety of the antibiotic hygromycin A in eight steps and 39 % overall yield from a non‐chiral starting material. The sequence made use of an initial enzymatic step to transfer chirality to an aromatic ring and was followed by selective organic chemistry transformations (oxidation, protection, azidation, hydrolysis) of the six‐membered ring in order to achieve the target. The approach is also amenable to the synthesis of other related unnatural analogues as exemplified by the synthesis of the C2 epimer of the natural aminocyclitol. All the intermediates were fully characterized, and the absolute stereochemistry assigned by spectrometric methods.

Advances across the chemical and biological (life) sciences are increasingly enabled by ideas and tools from sectors outside these disciplines, with information and communication technologies playing a key role across 21^stcentury scientific development. In the face of rapid technological change, the Organisation for the Prohibition of Chemical Weapons (OPCW), the implementing body of the Chemical Weapons Convention (“the Convention”), seeks technological opportunities to strengthen capabilities in the field of chemical disarmament. The OPCW Scientific Advisory Board (SAB) in its review of developments in science and technology examined the potential uses of emerging technologies for the implementation of the Convention at a workshop entitled “Innovative Technologies for Chemical Security”, held from 3 to 5 July 2017, in Rio de Janeiro, Brazil. The event, organized in cooperation with the International Union of Pure and Applied Chemistry (IUPAC), the National Academies of Science, Engineering and Medicine of the United States of America, the Brazilian Academy of Sciences, and the Brazilian Chemical Society, was attended by 45 scientists and engineers from 22 countries. Their insights into the use of innovative technological tools and how they might benefit chemical disarmament and non-proliferation informed the SAB’s report on developments in science and technology for the Fourth Review Conference of the Convention (to be held in November 2018), and are described herein, as are recommendations that the SAB submitted to the OPCW Director-General and the States Parties of the Convention. It is concluded that technologies exist or are under development that could be used for investigations, contingency, assistance and protection, reducing risks to inspectors, and enhancing sampling and analysis.

The Chemical Weapons Convention (CWC) is an international disarmament treaty that prohibits the development, stockpiling and use of chemical weapons. This treaty has 193 States Parties (nations for which the treaty is binding) and entered into force in 1997. The CWC contains schedules of chemicals that have been associated with chemical warfare programmes. These scheduled chemicals must be declared by the States that possess them and are subject to verification by the Organisation for the Prohibition of Chemical Weapons (OPCW, the implementing body of the CWC). Isotopically labelled and stereoisomeric variants of the scheduled chemicals have presented ambiguities for interpretation of the requirements of treaty implementation, and advice was sought from the OPCW’s Scientific Advisory Board (SAB) in 2016. The SAB recommended that isotopically labelled compounds or stereoisomers related to the parent compound specified in a schedule should be interpreted as belonging to the same schedule. This advice should benefit scientists and diplomats from the CWC’s State Parties to help ensure a consistent approach to their declarations of scheduled chemicals (which in turn supports both the correctness and completeness of declarations under the CWC). Herein, isotopically labelled and stereoisomeric variants of CWC-scheduled chemicals are reviewed, and the impact of the SAB advice in influencing a change to national licensing in one of the State Parties is discussed. This outcome, an update to national licensing governing compliance to an international treaty, serves as an example of the effectiveness of science diplomacy within an international disarmament treaty.