No abstract

No abstract

No abstract

Die α‐Aminotetrahydropyrane (I) reagieren mit den lithiumorganischen Verbindungen (II) bei ‐25°C unter Öffnung des Pyranringes in Ausbeuten zwischen 80 und 94% zu den 1‐Hydroxy‐5‐alkylamino‐alkanen (III), die sich in guten Ausbeuten zu den α‐substituierten Piperidinen (IV) cyclisieren lassen.

France, paralysed during many years of a cruel occupation, has been unable to maintain a sustained technical effort, comparable with that of England.Nevertheless, the work of French engineers was never discontinued. In difficult and sometimes dramatic circumstances, more often than not with only restricted facilities, their work of research continued, stubbornly and in silence.