The thermal decomposition of cyclobutanecarboxaldehyde p-tosylhydrazone, and, The reaction of silver tetrafluoroborate with organic chlorides.

Abstract

Part I. Aldehyde and ketone p-tosylhydrazones react thermally with bases in aprotic solvents to give diazo-compounds which decompose by carbenic processes. In proton-donor solvents decomposition appears to occur primarily by cationic mechanisms involving diazonium and/or carbonium ion intermediates. Thermal decomposition of cyclobutanecarboxaldehyde p-tosyl-hydrazone gives methylenecyclobutane by hydrogen migration, cyclopentene by ring expansion, bicyclo(2.1.0)pentane by intramolecular insertion, 2-methylbutene-1 by reorganization, methylcyclobutane by hydride transfer, along with ethylene and acetylene by fragmentation. The effect of varying solvents and bases on the product compositions is reported. A brief historical review is given and the mechanisms of this reaction are discussed. Part II. A new method for the preparation of organic fluoro-compounds was discovered. Reaction of cholesteryl chloride with silver tetrafluoroborate in monoglyme gave good yields of cholesteryl fluoride and cholesta-3,5-diene. In a similar way, 4-chloromethylfluorenone gave the corresponding fluoride as a principal product.