Constituents of the root of Dictamnus albus L.

In addition to several known constituents and their artefacts, the root of Dictamnus albus L. has yielded the new natural products, isomaculosidine (9) and preskimmianine (15, R== Me).²¹     

Synthesis of 2′-C-methyl-branched isonucleosides

Novel regioisomers of 2′-methyl-branched nucleosides were designed and synthesized to mimic potent anti-viral drugs like Valopicitabine. The short and efficient synthesis of the targets involves a one-pot tosylation/cyclization step that leads to an activated furan scaffold on which the isonucleosides were built.     

Ueber das gleichzeitige Vorkommen eines l?slichen Bleisalzes und freier Schwefels?ure im Sherry-Wein

Ohne Zusammenfassung     

Ueber ein Verfahren Bleiglanz und andere Bleiverbindungen auf nassem Wege in kurzer Zeit auf Blei zu probiren

Ohne Zusammenfassung     

Chlorsaures Kali und Salpeters?ure als Oxydationsmittel

Ohne Zusammenfassung     

The enantioselective synthesis of (R)- and (S)-3-amino-3,4-dihydro-1H-[1,8]naphthyridin-2-one

A number of approaches to the enantioselective synthesis of (R)- and (S)-3-amino-3,4-dihydro-1H-[1,8]naphthyridin-2-one were studied. A novel one-pot asymmetric reduction/lactamization provided the desired products in high yield and enantiomeric excess.     

An approximate dynamic programming approach for the vehicle routing problem with stochastic demands

This paper examines approximate dynamic programming algorithms for the single-vehicle routing problem with stochastic demands from a dynamic or reoptimization perspective. The methods extend the rollout algorithm by implementing different base sequences (i.e. a priori solutions), look-ahead policies, and pruning schemes. The paper also considers computing the cost-to-go with Monte Carlo simulation in addition to direct approaches. The best new method found is a two-step lookahead rollout started with a stochastic base sequence. The routing cost is about 4.8% less than the one-step rollout algorithm started with a deterministic sequence. Results also show that Monte Carlo cost-to-go estimation reduces computation time 65% in large instances with little or no loss in solution quality. Moreover, the paper compares results to the perfect information case from solving exact a posteriori solutions for sampled vehicle routing problems. The confidence interval for the overall mean difference is (3.56%, 4.11%).     

Solution-phase combinatorial chemistry

The use of solution phase techniques has been explored as an alternative to solid-phase chemistry approaches for the preparation of arrays of compounds in the drug discovery process. Solution-phase work is free from some of the constraints of solid-phase approaches but has disadvantages with respect to purification. This article will also illustrate some of the advances made in recent years in solution phase array chemistry including using supported reagents and simple extractive protocols for the effective preparation of high quality samples.