Tetrahedron letters

Base induced skeletal rearrangements via spirocyclic ipso intermediates in dibenzodithiocinium salts

K Ohkata, K Okada, K Maruyama, K Akiba

Index: Ohkata, Katsuo; Okada, Keiji; Maruyama, Kohji; Akiba, Kin-ya Tetrahedron Letters, 1986 , vol. 27, # 28 p. 3257 - 3260

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Citation Number: 10

Abstract

Treatment of 6-methyl-12-oxo-5H,7H-dibenzo[b,g] [1,5]-dithiociniumsalt ( ) with methanolic KOH afforded the ring contracted product ( ), ie, thiepin derivatives, trans- . (44%) and cis-2a (19%). However, the corresponding deoxodithiociniumsalt ( ) gave an unexpected isomer ( ) with the same thiepin skeleton. These are explained by tandem sigmatropy. ... A novel rearrangement of , via tandem sigmatropy is described. ... : mp 178–181.5 °C; the conformation has been ...