RESUMO
The biosynthesis of the meroterpenoid guajadial was previously hypothesized to occur via a hetero-Diels-Alder reaction between caryophyllene and an o-quinone methide. This hypothesis has been verified via the biomimetic synthesis of guajadial and psidial A in an aqueous three-component coupling reaction, between caryophyllene, benzaldehyde, and diformylphloroglucinol.
Assuntos
Biomimética , Sesquiterpenos/síntese química , Terpenos/síntese química , Modelos Moleculares , Conformação Molecular , Sesquiterpenos/química , Terpenos/químicaRESUMO
The partial reduction of electron deficient pyrroles is an extremely versatile method that allows us to prepare substituted pyrrolidines and pyrrolizidines with trans-diol stereochemistry on the five membered ring.
Assuntos
Alcaloides de Pirrolizidina/síntese química , Sorbitol/análogos & derivados , Pirróis/química , Alcaloides de Pirrolizidina/química , Sorbitol/síntese química , Sorbitol/química , EstereoisomerismoRESUMO
The effect of Cu(II) on the determination of homocysteine via its electrochemically initiated reaction with N, N-diethyl-p-phenylenediamine is examined. The presence of copper inhibited the detection process for homocysteine owing to a complexation reaction occurring. This provided an indirect route for the sensitive and selective determination of Cu(II), which produced a linear response over the range from 2.5 to 500 microM and a limit of detection of 2.5 microM. The detection pathway was examined in the presence of metallic and inorganic ions, with negligible interference observed.
