Refluxing of tris-(2,6-dimethoxyphenyl)carbenium hydrogen dichloride (2b)-2H2O with chloroform furnished 9-(2,6-dimethoxyphenyl)-1,8- dimethoxyxanthene (11). This cyclization process with concomitant hydride transfer to the central carbon atom is rationalized by assuming concerted breakdown of any of the intermediates (6), (7), and (9) (Scheme 3), i.e. the operation of the intramolecular version of the disputed Olah-Svoboda mechanism of hydride transfer to triarylcarbenium ions.
|Number of pages||4|
|Journal||Journal of the Chemical Society, Perkin Transactions 2|
|Publication status||Published - Dec 1 1985|
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