Reactivities of stable rotamers. XLIII. Diazotization of 2-methyl-2-(1,2,3,4-tetrachloro- and 1,4-dimethoxy-9-triptycyl)propylamine rotamers

The title amines were prepared from the corresponding rotamers of carboxyli c acids via azides and isocyanates. Diaiotization of these amines with isop entyl nitrite and organic acids commonly afforded olefins, that are derived from Wagner-Meerwein type rearrangement of the intervening cation followed by deprotonation. Other products included a cyclic compound derived by the attack of the carbocation on an unsubstituted benzene bridge and esters de rived from the acid which was used for diazotization. These two compounds a re the products from the cation prior to the rearrangement. The sc-tetrachl oro compound afforded the esters of the organic acids as almost an exclusiv e product and the sc-dimethoxy compound afforded a cyclized compound which is derived from the nucleophilic reaction of the I-methoxy group with the c ation, followed by demethylation of the resulting oxonium ion. These featur es are attributed to the strong interaction of the l-substituent with the i ntermediate carbocations. In agreement with this interpretation, the format ion of the corresponding ester is decreased with decreasing the nucleophili city of the acid used for the diazotization of the sc-tetrachloro compound.