Base induced skeletal rearrangements via spirocyclic ipso intermediates in dibenzodithiocinium salts

✍ Scribed by Katsuo Ohkata; Keiji Okada; Kohji Maruyama; Kin-ya Akiba

• Book ID: 104218849
• Publisher: Elsevier Science
• Year: 1986
• Tongue: French
• Weight: 228 KB
• Volume: 27
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)84768-1

✦ Synopsis

Treatment of 6-methyl-12-oxo-5H,7H-dibenzo[b,g][l,5]dithiocinium salt (&) with methanolic KOH afforded the ring contracted product (a), i. e., thiepin derivatives, trans-z (44%) and cis-2a (19%). However, the corresponding deoxodithiocinium salt (2) gave an unexpected isomer (3) with the same thiepin skeleton. These are explained by tandem sigmatropy.