Reactivity of Stable Rotamers. XXXV. Diazotization of 2-(1,4-Dimethyl-9-triptycyl)-2-methylpropylamine Rotamers

Article abstract of DOI:10.1246/bcsj.68.1485

The title amine rotamers were prepared from the corresponding carboxylic acids and were diazotized with isopentyl nitrite in the presence of acetic acid in benzene.The ap rotamer affords, as main products, olefins that are derived by deprotonation after rearrangement of the intervening carbocation and small amounts each of the corresponding acetate and a cyclized product, both of which are derived from the unrearranged cation.By contrast, the olefins a minor products and a cyclized product, which is formally derived by insertion of the intervening cation to a C-H bond of the 1-methyl group before rearrangement, is main in the case of the sc isomer.This cyclic product was synthesized independently.The yield of the corresponding acetate is increased to a considerable extent in the case of the sc relative to the ap.These results in the reaction of the sc are discussed in terms of stabilization of the intervening cation by the C-H bond.