Reactions of 1,2,4‐Oxadiazole[4,5‐a]piridinium Salts with Alcohols: the Synthesis of Alkoxybutadienyl 1,2,4‐Oxadiazoles

oleh: Dr. Mattia Moiola, Dr. Marco Leusciatti, Prof. Dr. Paolo Quadrelli

Format: Article
Diterbitkan: Wiley-VCH 2020-02-01

Deskripsi

Abstract 1,2,4‐Oxadiazole[4,5‐a]piridinium salts add alcohols and alkoxides to undergo electrocyclic ring opening affording alkoxybutadienyl 1,2,4‐oxadiazole derivatives. The pyridinium salts represent a special class of Zincke salts that are prone to rearrange to give alkoxybutadienyl 1,2,4‐oxadiazoles when treated with suitable nucleophiles or, alternatively, to give pyridones in the presence of bicarbonate. The pivotal tuning of the experimental conditions leads to a straightforward synthesis of valuable 1,2,4‐oxadiazole derivatives. The mechanism is also discussed in the light of previous observations.