Stibatriptycene (1c) has been synthesized by cyclization of 9-(o-chlorophenyl)-9, 10-dihydro- 9-stibaanthracene (2c) with an excess of lithium piperidide. The general applicability of this ring closure reaction, first developed for the synthesis of phosphatriptycene (1a) and presumed to proceed by nucleophilic attack of a carbanionic centre on a (slowly generated) benzyne, has further been demonstrated by a new synthesis of the known arsatriptycene ( ...
