The debrominative reduction of 2-bromoisopinocamphone with metal hydrides

✍ Scribed by David J. Goldsmith; R.C. Joines

• Book ID: 104223291
• Publisher: Elsevier Science
• Year: 1965
• Tongue: French
• Weight: 197 KB
• Volume: 6
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)90151-5

✦ Synopsis

Although the action of metal hydrides on a-haloketones generally leads to halohydrins (1) a number of exceptions have been reported. In these, the debrominated ketone has been obtained instead (2). We wish to report here the results of the hydride reduction of a bromoketone which yields almost exclusively debrominated products. Bromination of the enol acetate 1 yields 2-bromoisopinocsmphone, 1 (3). Reduction of br 2 the latter with a large excess of sodium borohydride in 95% ethanol gave no detectable bromohydrin. The product mixture contained, however, 73% (4) of neoisopinocampheol, 2, identified by comparison of its NMR spectrum to that reported for 3 (5), by stereosnecific oxidation to isopinocamphone (5) and by its lack of identity (g.c. retention time) with an authentic