Studies of bridged benzoheterocycles. Part III. Cycloadditions of 1,4-epoxy-1,4-dihydronaphthalene to some dipolar compounds and dienes

Abstract

The nature of the 1,4-epoxy-1,4-dihydronaphthalene skeleton was studied by performing MO calculations and by investigating cycloadditions to some dipolar compounds and dienes. Reactions of 1,4-epoxy-1,4-dihydronaphthalene (I) with phenylglyoxylonitrile oxide, 1-methylpyridinium-3-olate, ethyl azidoformate, and phenyl azide gave the corresponding 1:1 adducts. Similar treatments of compound (I) with benzenesulphonyl and tosyl azides afforded only imine derivatives. The reaction of compound (I) with 6,6-dimethylfulvene yielded a mixure of isomeric 1 : 1 and 1 : 2 adducts. The stereochemistry of the adducts is discussed in the light of spectroscopic data. Their thermal behaviour is also reported.