A number of pentopyranoside derivatives were treated with Me 3 Al in order to investigate the influence of structural parameters on the methyl group transfer in the endocyclic alkylative cleavage reaction of these substrates. A cyclic CH ··· O hydrogen bonded model is suggested as an intermediate, which is used to explain the stereoselectivities for different substrates. In several, cases the dia

The results presented are the first examples where organotitanium reagents induced alkylative endo-cleavage of carbohydrates. The best conditions for the alkylative transfer of a methyl group to benzyl 2-deoxy- 2-C-methyl-4-O-(tert-butyldimethylsilyl)-α-D-arabinopyranoside (1) were the application of one equivalent of AlMe3 followed by four equivalents of MeTiCl3 generated by mixing TiCl4 and ZnMe

An efficient enantiospecific synthesis of D-erythro-sphingosine (1) via azidosphingosine (2) is described, the absolute stereochemistry being derived from D-tartaric acid.

Ledare

Om postfordistiska ekonomier, globala produktionskedjor och tv-serier.

Up until the mid 1960s you could still find significant remains of a medieval brick house in Halmstad. Since the building was rediscovered in the 1920s, numerous speculations about the house and its owners have been presented. It has been linked to the Kalente guild as well as to the guild of St. Gertrud. These hypotheses rest, however, on very flimsy basis. Thus, this article examines a whole newUp until the mid 1960s you could still findsignificant remains of a medieval brick housein Halmstad. Since the building was rediscoveredin the 1920s, numerous speculationsabout the house and its owners have beenpresented. It has been linked to the Kalenteguild as well as to the guild of St. Gertrud.These hypotheses rest, however, on veryflimsy basis. Thus, this article examines awhole new hypothes

På senare tid har allt fler aktörer engagerat sig för att ”hjälpa bina” och motverka bidöd. Men när köpcentrum, snabbmatskedjor och fastighetsbolag satsar på bikupor för honungsbin i stället för att hjälpa vilda bin riskerar man att göra mer skada än nytta, skriver fyra Lundaforskare, som uppmanar företagen att hjälpa till på rätt sätt.

Since the end of the Cold War, migration law and policy of the global North has been characterised by externalisation, privatisation and securitisation. These developments have been conceptualised as denying access to migrants and as politics of non-entrée. This article proposes to broaden the analysis, and to analyse unwanted migration as merely one form of international human mobility by relying

We will present the formation of nanoparticle chains by deposit magnetic iron oxide aerosol nanoparticles in a combined electric and magnetic field. Aerosol methods, in particular spark ablation, provides a good means to produce magnetic nanoparticles with a controllable size and concentration in a broad size range without agglomeration. These aerosol nanoparticles are usually deposited using an e

Nanowire (NW) Photovoltaics are a promising route for low-cost multi-bandgap tandem cells, which is taxing in terms of processing and lattice matching in traditional planar geometries.[1] III-V nanowires are more suitable for monolithic integration as they can assimilate the lattice mismatch to a larger extent.[2] GaAsP is a material that offers a wide tunability of the band gap from near infrared

Thin organic coatings (TOC) or paints on hot dip galvanized steel (HDGS) improve the corrosion properties and create visually pleasing surfaces. Delamination of these coatings leads to corrosion and peeling of the paints. Hence, a novel method for improved adhesion and corrosion properties for HDGS surfaces is introduced. It is shown how the fabrication of a nanomolecular silane film as an interfa

Generally, low temperatures are favourable for district heating (DH) systems, while several factors limit how low temperatures can actually be. The history of DH is characterized by a constant strive for lower temperatures. In order to stay competitive, and increase its market share, the DH industry must continue the work towards even lower temperatures. This chapter goes through the impressive re

Magnetic nanoparticles have shown great potential for use in drug delivery and bioimaging applications and are prospective building blocks in future high-performing permanent magnets. Today, magnetic nanoparticles are most often produced in batches by chemical methods resulting in the risk of chemical impurities and production of vast amounts of chemical waste. Aerosol generation methods on the ot

The synthesis of core@shell nanoparticles has predominantly been carried out by chemical methods or physical deposition of a shell material post-growth onto core particles. By combining immiscible materials that differ in surface energy, we demonstrate the spontaneous atomic rearrangement to monodisperse Cu@Ag core@shell particles directly in the aerosol phase, starting from pure Cu and Ag electro