Invariance of selfinjective algebras of quasitilted type under stable equivalences

We prove that the class of finite dimensional selfinjective algebras over a field which admit Galois coverings by the repetitive algebras of the quasitilted algebras, with Galois groups generated by compositions of the Nakayama automorphisms with strictly positive automorphisms, is invariant under stable and derived equivalences. Dedicated to Claus Michael Ringel on the occasion of his sixtieth birthday     

On the relaxation of trapped electrons in glassy hydrocarbons irradiated at 4 K

In contrast to previous reports e^?_t in 3MHx produced at 4 K shows trap relaxation when warmed to 77 K. The relaxation in 3 MHx and 3MP occurs without loss of e^?_t, and results in an increase in ?_max as well as a shift of λ_max.     

A new route to 1-phenylnaphthalenes by cycloaddition: a simple and selective synthesis of some naphthalene lignan lactones

2-(2-Dithianyl)benzhydrols ($\text{2}$ a-c) undergo facile cycloaddition reaction with maleic anhydride under thermal conditions to give 1-phenyl-naphthalenes ($\text{7}$ a-c) in one step. The naphthalenes ($\text{7}$ a-c) have been converted into the naphthalene lignan lactones, ($\text{9}$ a-c) and ($\text{10}$ a-c).     

Cis-trans isomerization of iodine-doped polyacetylene

A quantitative analysis of the cis—trans isomerization of the lightly doped polyacetylene with iodine at room temperature is reported. The cis—trans ratio was determined on the basis of the infrared absorption measurement. The result clearly demonstrates the promotion of the isomerization with increase in the dopant concentration. The degree of the amount of the isomerization, however, is rather small compared with the previous study based on the nuclear magnetic resonance measurement.     

Site-specific alkylation of tetra-alkylpyrroles

Intramolecular cyclisation of the trifluoromethanesulphonate esters of the β-(4-hydroxy-n-butyl)-pyrroles (5a) and (5b) in each case yields a mixture of the α- and β-alkylated products whereas exclusive β-alkylation is observed for the β-(5-hydroxy-n-pentyl)-pyrrole (5c).     

Consecutive elongation of alanine oligopeptides at the second time range under hydrothermal conditions using a microflow reactor system

During the course of the study of the hydrothermal stability of alanine oligopeptides, a small amount of oligopeptides longer than the starting oligopeptides was found in the reaction products. On the basis of this unexpected finding and the investigation of the reaction mechanism, the elongation of oligopeptides using (Ala)3, (Ala)4, and (Ala)5 was attempted in aqueous solution at 275-310 degrees C within the second time range using a microflow reactor system. The elongation of (Ala)4 and (Ala)5 succeeded in the presence of an excess amount of Ala monomer. This is probably due to the fact that the elongation rate is competitive or somewhat faster than the degradation of peptide bonding. On the contrary, the elongation of (Ala)3 was not possible since it was immediately converted to diketopiperazine.