Reinvestigation of base-induced skeletal conversion via a spirocyclic intermediate of dibenzodithiocinium derivatives and a computational study using the HF/6-31G* basis set
作者:Keiji Okada、Masato Tanaka
DOI:10.1039/b205588k
日期:2002.11.26
6-methyl-12-oxo-5H,7H-dibenzo[b,g][1,5]dithiocinium salt (1a) with methanolic KOH afforded a mixture of dibenzothiepin derivative 5 in 66% yield. The rearrangement was explained in terms of usual [2,3]-sigmatropic shift via a spirocyclic intermediate. However, an unique rearrangement via an alternative spirocyclic intermediate was observed in 6-methyl-5H,7H-dibenzo[b,g][1,5]dithiocinium salt (2) to give