RESONANCE-STABILIZED ALPHA-NAPHTHYLMETHYL CARBOCATIONS AND DERIVED SPIRO COMPOUNDS .4. TRANSFORMATIONS OF 4-DIMETHYLAMINO-5-METHOXYNAPHTHYLMETHYL CARBOCATION IN THE PRESENCE OF PROTIC AND LEWIS-ACIDS - THE FORMATION OF AN ASYMMETRICAL SPIRO COMPOUND

4-Dimethylamino-5-methoxynaphthylmethyl carbocation generated from hyd roxymethyl-4-dimethyiamino-5-methoxynaphthalene in trifluoroacetic aci d behaves as both diene and dienophile and undergoes (4 pi + 2 pi) cyc loaddition to give an asymmetrical spiro compound. The other reaction product is ethylamino)-5,5'-dimethoxy-1,1'-dinaphthylmethane, which is formed via ipso-substitution of the hydroxymethyl group in the initia l alcohol. When this cation is generated on Al2O3, 4-dimethylamino-5-m ethoxy-1-naphthaldehyde is formed along with the substituted dinaphthy lmethane.