The Claisen rearrangement of sugar derived allyl vinyl ether, Wittig olefination and intramolecular acetalization reactions were used as key steps in the first stereoselective total synthesis of neosemburin and isoneosemburin through the formation of a 3-C-branched sugar precursor as a key intermediate.

Tetrasubstituted (Z)-alkenes were readily prepared through the Horner-Wadsworth-Emmons reactions of methyl 2-[bis(2,2,2-trifluoroethyl)phosphono]propionate with aryl alkyl ketones by employing Sn(OSO(2)CF(3))(2) and N-ethylpiperidine.

The use of surface-bound alkyl and phenyl groups as synthetic vehicles in coupling reactions on oxygen-activated Au(111) is demonstrated by the formation of ethers via alkyl and phenyl iodides. Ethers are formed by successive additions of surface-bound alkyl groups to adsorbed atomic oxygen to form first the alkoxy and then the ether. The addition of the ethyl group to adsorbed oxygen on Au(111...

A novel methodology, based on the use of phosphorescence imaging, is applied to determine the local through-thickness velocity profile of lubricant in an elastohydrodynamic contact. The technique has spatial and temporal resolutions of 40 μm and 340 μs respectively and thus allows lubricant rheology to be investigated at conditions close to service conditions. The capability of the newly-develo...

We report on the collapsing and reswelling ability of grafted poly(methyl vinyl ether) chains of different molecular architectures. In order to study the influence of constraints and confinement of the chains, the polymer was grafted onto AFM tips, as a model of a curved nano-sized surface, and onto macroscopic silicon substrates for comparison purposes. AFM-based force spectroscopy experiments...

Cellular damage and inflammatory processes cause activation of phospholipase A in plasma membranes resulting in the production of various lysophospholipids. Treatment of mice with L-alpha-lysophosphatidylcholine, a decomposition product of phosphatidylcholine, greatly stimulates mouse peritoneal macrophages to ingest target cells via the Fc receptors. Similarly, treatment of mice with L-alpha-l...

The alkaline-earth element bis(trimethylsilyl)amides, [Ae{N(SiMe3 )2 }2 (thf)2 ] [Ae=Mg, Ca, Sr], are effective precatalysts for boron-nitrogen bond formation through the desilacoupling of amines, RR'NH (R=alkyl, aryl; R'=H, alkyl, aryl), and pinBSiMe2 Ph. This reactivity also yields a stoichiometric quantity of Me2 PhSiH and provides the first example of a catalytic main-group element-element ...

Chemical bond breaking and formation during chemical reactions can be observed using "transition state spectroscopy". Comparing the measurement result of the transition state spectroscopy with the simulation result of single direct-dynamics trajectory, we have elucidated the reaction dynamics of Claisen rearrangement of allyl vinyl ether. Observed the reaction of the neat sample liquid, we have...

Natural O-alkyl-glycerolipids, also known as alkyl-ether-lipids (AEL), feature a long fatty alkyl chain linked to the glycerol unit by an ether bond. AEL are ubiquitously found in different tissues but, are abundant in shark liver oil, breast milk, red blood cells, blood plasma, and bone marrow. Only a few AEL are commercially available, while many others with saturated or mono-unsaturated alky...