Borohydride reduction of piridinium salts. IV. Simultaneous low temperature formation of (2+2) and (4+2) cycloadducts in the reduction of 1-methyl-4-cyano-pyridinium iodide

✍ Scribed by F. Liberatore; A. Casini; V. Carelli; A. Arnone; R. Mondelli

• Publisher: Elsevier Science
• Year: 1971
• Tongue: French
• Weight: 244 KB
• Volume: 12
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)97300-9

✦ Synopsis

In a previous paper (1) we reported the formation of the cycloadduct V, in the borohydride reduction of the pyridinium salt I. If the reduction is carried out at -45" in 0.8N methanolic NaOH the insoluble product IV is formed (60% yield), containing only traces of compound V. However, reductions carried out at tempera tures increasing from -45" to -20°, give rise to precipitates containing progreg sively more of V (e.g.