Chiral Organosiucon Compounds. Part 1. Synthesis of Chiral Silyl Enol Ethers

A convenient synthesis of menthol- and borneol-derived chiral silyl enol ethers is described.     

Diastereoselectivity in α-Benzylation Reactions of Esters of Spiro[bornane-3,2′-indan]-2-exo-ol

The α-benzylation of a series of alkanoic esters of spiro[bornane-3,2′-indan]-2-exo-ol has been investigated and shown to proceed in 9–60% d.e.     

Asymmetric Simmons-Smith Cyclopropanation Of α,β-Unsaturated Bornane-2,3-Diol Acetals

Reactionofselected α, β-unsaturated aldehydes with bornane-2-exo,3-cxo-diol has afforded a series of novel, chiral acetals which, on treatment with a Simmons-Smithreagent, undergo diastereoselective(46 - 70 %d.e.) cyclopropanatioa     

Benzodiazepine Analogues. Part 8.1 Trimethylsilyl Azide Mediated Schmidt Rearrangement of Thioflavanone and Thiochromanone Precursors

The synthesis and Schmidt rearrangment of a series of thioflavanone analogues to benzothiazepinone derivatives is described.     

Dry deposition of pollutant and marker particles onto live mouse airway surfaces enhances monitoring of individual particle mucociliary transit behaviour

Particles suspended in the air are inhaled during normal respiration and unless cleared by airway defences, such as the mucociliary transit (MCT) system, they can remain and affect lung and airway health. Synchrotron phase‐contrast X‐ray imaging (PCXI) methods have been developed to non‐invasively monitor the behaviour of individual particles in live mouse airways and in previous studies the MCT behaviour of particles and fibres in the airways of live mice after deposition in a saline carrier fluid have been examined. In this study a range of common respirable pollutant particles (lead dust, quarry dust and fibreglass fibres) as well as marker particles (hollow glass micro‐spheres) were delivered into the trachea of live mice using a dry powder insufflator to more accurately mimic normal environmental particulate exposure and deposition via inhalation. The behaviour of the particles once delivered onto the airway surface was tracked over a five minute period via PCXI. All particles were visible after deposition. Fibreglass fibres remained stationary throughout while all other particle types transited the tracheal surface throughout the imaging period. In all cases the majority of the particle deposition and any airway surface activity was located close to the dorsal tracheal wall. Both the individual and bulk motions of the glass bead marker particles were visible and their behaviour enabled otherwise hidden MCT patterns to be revealed. This study verified the value of PCXI for examining the post‐deposition particulate MCT behaviour in the mouse trachea and highlighted that MCT is not a uniform process as suggested by radiolabel studies. It also directly revealed the advantages of dry particle delivery for establishing adequate particulate presence for visualizing MCT behaviour. The MCT behaviour and rate seen after dry particle delivery was different from that in previous carrier‐fluid studies. It is proposed that dry particle delivery is essential for producing environmentally realistic particle deposition and studying how living airway surfaces handle different types of inhaled particles by MCT processes.