抄録
Spiro compound 3a was synthesized by the platinum catalyzed oxidation of indolomorphinan 1 followed by treatment of 2a with DBU. Reaction of compound 3a with boron tribromide gave the compound 3b, concomitantly with compound 2b. The Lewis acid, boron tribromide could facilitate the simultaneous demethylation and reverse rearrangement from spiro compound 3b to indolenin 2b. This reverse rearrangement reaction has not yet been reported. We are now examining various Lewis acid to give reverse rearrangement. These results will also be discussed.
