Woelm, aluminum oxide

Geminal difluorides usually require a strong base for conversion to vinylic fluorides, but some aluminum oxides, such as neutral y-alumina or Woelm aluminum oxide, result in ready de-hydrofluorination under unexpectedly mild conditions. Just stirring the geminal difluorides 49 and 51 with a large excess of alumina at room or slightly elevated temperature affords products 50 and 52, respectively.84-85... 

Geminal difluorides usually require a strong base for conversion to vinylic fluorides, but some aluminum oxides such as neutral y-alumina or Woelm alumi-... 

Isolation of Antimicrobial Alkaloids from Tertiary Non-phenolic Base Fraction - A 2 g portion of the crude nonphenolic base fraction was dissolved in chloroform and chromatographed over 200 g of aluminum oxide (Woelm, neutral, grade III). The solvents used were 300 ml of chloroform, 500 ml of 1Z methanol in chloroform, 300 ml of 2Z metha-... 

Neutral aluminum oxide (activity III, Woelm) was used. 

The submitters used Merck 71707 aluminum oxide. The checkers used Woelm neutral alumina, Activity I. 

Aluminum Oxide Woelm neutral, activity grade 1, available from M. Woelm, Eschwege, Germany, was used. The column dimensions were 2.9 cm. X 29 cm., and the alumina was placed in the column with w-hexane. 

Chloral (trichloroacetaldehyde), CCI3CHO, oxidizes secondary alcohols to ketones in the presence of very active aluminum oxide (Woelm). This reaction seems to be superior to the Oppenauer oxidation, because it takes place at room temperature or at only slightly elevated temperatures [958, 959, 960],... 

Aluminum oxide, Woelm, activity grade V, 15-fold excess, eluted with 2 ml of each solvent per gram of aluminum oxide. Figures referring to ethyl acetate in italics. 

---