Synthesis of indoles condensed with a bicyclo[3.3.1]nonane skeleton

Different routes for the construction of biologically active diversely functionalized bicyclo[3.3.1]nonanes: an exploration of new perspectives for anticancer chemotherapeutics

“…The reaction proceeds with an intermediate hydrazone formation to produce the diindolyl product 578. 288,289 The synthesis of the corresponding monoindoles is quite difficult and requires a modied approach. Thus, dione 577 was rst converted into its monoacetal 579, which on treatment with phenyl hydrazine in the presence of acetic acid yielded the monoindolyl monoketal 580.…”