13C and 1H NMR of 2,6-diaryl-1-hydroxy piperidin-4-one oximes; substituent effects on cis/trans ratio and conformational equilibria.

The reaction of substituted diarylidene acetones with hydroxylamine hydrochloride affords isomeric N-hydroxy diaryl piperidinone oximes as main products. The structures as well as conformational equilibria of these products were established by 1H and 13C NMR spectroscopy and further studied by variable temperature NMR. It was found that the cis/trans ratio of 2,6-substituted piperidine derivatives depended on the position of the substituent on the aromatic ring.

[Tetanus in adults: mortality. Study in 130 cases]. / Tétanos del adulto: mortalidad. Estudio en 130 casos.

Out of the 557 cases of tetanus in adult patients seen in our institution over 61 years, we have selected for analysis the 130 patients who where admitted to our service since its creation in 1968. We have found a trend toward older patient age in recent years. The age distribution showed a bimodal curve which was maintained in the different periods and was due, in the last one to the population of parenteral drug abusers. In the last 20 years there has been an increase in severe forms (p less than 0.001). The mortality was statistically associated with clinical severity (p less than 0.001) and with the surgical portal of entry (p less than 0.05). The development of intensive care reduced the mortality rate from 58.3% in the period before ICU to 24.6% in the 130 patients cared for since the service was created (p less than 0.001). In the last 10 years, the mortality rate of 41 patients was 9.7%. The most common cause of death was cardiac arrest (68.7%). Superinfection was the second cause (25%). The use of beta-blockers in patients with severe tetanus, with significant autonomic abnormalities, reduced the mortality from 72.7% to 14.8% (p less than 0.001). The mortality of superinfection has been maintained, without statistically significant changes.

Reaction of dibenzalacetone with hydroxylamine hydrochloride under phase-transfer conditions. 1 H and 13 C 2D NMR structural elucidation of the products.

The constitution, configuration and conformation of three N-hydroxydiphenylpiperidines were established by 1 H and 13 C 2D NMR spectroscopy. The products were obtained using phase-transfer conditions.