Comparison of Prioritization Techniques Using Interhierarchy Mappings

This paper discusses a method of comparing different prioritization techniques that entails mapping the input data from one system to another. The ranking vectors output by the methods should then be comparable. As an illustration, a method that uses pairwise comparison, e.g. the Analytic Hierarchy Process (AHP) of Saaty, itself viewed as a mapping, is compared with a method using cross impact analysis, the Edinburgh Approach. The problem centres on an appropriate inverse of the process mapping. Although the discussion is restricted to simple bilevel hierarchies, useful insight is provided into the methodologies in general and, in particular, the problem of inverse inconsistency associated with rank reversals. A way in which the theory of AHP might be incorporated into a Differential Hierarchy Process is suggested.     

Two enantiomerically pure cyclic arenesulfonamide hydrochloride salts

The crystal structures of N‐[(1R)‐1‐(1‐naphthyl)ethyl]‐3,4‐dihydro‐2H‐1,2‐benzothiazin‐4‐aminium 1,1‐dioxide chloride, C₂₀H₂₁N₂O₂S⁺·Cl⁻, (I), a six‐membered cyclic sulfonamide, and (1R)‐N‐[(5,5‐dioxo‐6,7‐dihydrodibenzo[d,f][1,2]thiazepin‐7‐yl)methyl]‐1‐(1‐naphthyl)ethanaminium chloride, C₂₆H₂₅N₂O₂S⁺·Cl⁻, (II), a seven‐membered cyclic sulfonamide, both representative of a novel family of agonists of the extracellular calcium sensing receptor (CaSR) of possible clinical importance, are reported. The known chirality of the naphthylethylamine precursor has enabled assignment of the absolute configuration of both compounds, which is crucial for the receptor recognition. The crystal structures, though different, reveal for these agonists a notable absence of intramolecular π–π stacking between their respective aromatic groups. This suggests a common structural feature that allows CaSR agonists to be distinguished from antagonists, since in the latter, such interactions have been shown to be important. The connectivities between molecules in the crystal structures are also different, but both involve hydrogen bonding mediated by chloride ions as a common dominant feature.     

Intramolecular PhI=O mediated copper-catalyzed aziridination of unsaturated sulfamates: a new direct access to polysubstituted amines from simple homoallylic alcohols

[reaction: see text] Olefinic sulfamates derived from primary and secondary alcohols undergo intramolecular copper-catalyzed aziridination in the presence of iodosylbenzene to afford novel bicyclic fused aziridines. The latter were opened by various nucleophiles to give the corresponding substituted cyclic sulfamates, which in turn reacted, after nitrogen activation, with a second nucleophile at the carbon atom bearing the oxygen atom. Concomitant removal of the sulfonyloxy moiety thus gave access to polysubstituted amines.     

Synthesis of 1,4-benzodiazepine-1-carbothioamides,bicyclic analogues of the TIBO-type anti-HIV agents

A series of N'-substituted 1,4 -benzodiazepine-1-carbothioamides 2a-j were prepared by reacting the precursor 1,4-benzodiazepine 11 with the corresponding N-substituted isothiocyanates 2a-i or with sodium thiocyanate-trifluoroacetic acid (2j) . Despite the structural ressemblance of these molecules with the potent TIBO-type anti-HIV compound R82150, 2a-j displayed no anti-HIV activity in vitro.     

Arsenic speciation in clams of British Columbia

The water-soluble arsenic compounds in five species of clams – Butter clam (Saxidomus giganteus), Horse clam (Schizothoerus nuttalli), Soft-shelled clam (Mya arenaria), Native littleneck clam (Protothaca staminea), and Manila clam (Venerupis japonica) – are described. Varying amounts of arsenobetaine and tetramethylarsonium ion are the major arsenicals found in all species. Butter clams show the presence of a third compound which appears to be trimethylarsine oxide. Small amounts of as-yet-unidentified arsenicals can also be isolated.     

Synthesis of cyclic sulfonamides via intramolecular copper-catalyzed reaction of unsaturated iminoiodinanes

Olefinic primary sulfonamides were treated with iodobenzene diacetate and potassium hydroxide in methanol to give intermediate iminoiodinanes. Catalytic copper(I) or (II) triflate then provided intramolecular nitrene delivery leading to aziridine formation except in one case where a rare copper-catalyzed C-H insertion was observed. The aziridines could be opened by various nucleophiles (methanol, thiophenol, allylmagnesium bromide, benzylamine) to give the corresponding substituted cyclic sulfonamides.