Semiempirical and ab initio quantum chemical computations indicate that the intermediate formed prior to the selectivity-determining methyl transfer step in the reaction between glycosides and trimethylaluminum is a strongly hydrogen-bended equilibrium OH...C = O-H...C, which is proposed to be an important selectivity promoting factor in the alkyl transfer reaction.

The primary aim of this thesis is to develop a theoretical model that enhances our understanding of entrepreneurial learning as a process by which personalized streams of experience become routinized and embedded in venture-wide behaviors. The aim is realized by exploring entrepreneurial learning as an experiential multilevel process. This process begins with learning at the individual level, whic

Simple lactol ethers undergo ring cleavage to give acyclic chain-extended products on treatment with organoaluminium and organotitanium reagents.

Combinations of Lewis acids and nucleophilic reagents trigger endo-opening of the furanoside ring of methyl furanosides 1, 10 and 13, resulting in the attachment of the nucleophilic group at C-1 of the carbohydrate. The stereoselectivity in the C-C bond-forming step is low for the 2-deoxyfuranosides but very high (dr 1:99) for the furanosides carrying a methoxy group in the 2-position when a combi

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.

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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