FULLY CONJUGATED RINGS REACTIVITY OF SUBSTITUENTS

FULLY CONJUGATED RINGS REACTIVITY OF SUBSTITUENTS 2.12.4.1 Fused Benzene Rings... 

Reactions of Hydrogenated Derivatives of Fully Conjugated Ring Compounds Reactivity of Substituents Attached to Ring Carbon Atoms... 

In this chapter we summarize the reactivity of the six-membered heterocyclic compounds. We describe first the aromatic compounds, where aromatic is defined as fully conjugated round the ring, and then the partially and fully saturated compounds. Within each of these sections we discuss first the reactivity at the ring atoms, then the reactivity of substituent groups. 

The solvolysis rate constant of 3-indenyl 3,5-dinitrobenzoate 44a was 10 less than that of cyclo-pentenyl dinitrobenzoate 44d and 5 x 10 less than that of indanyl dinitrobenzoate 44b. Methoxy and methyl substituents at the 6-position on the ring in 44a and a methyl substituent at the 1-position on the double bond have accelerating effects expected for benzylic and allylic stabilization, respectively. The cyclopropanated system 44c showed no enhancement of reactivity compared to 44b, and this was taken as evidence for a diminuation in reactivity for 44c by a factor of 10 from that expected for a fully conjugating cyclopropyl group. The rate retardation was ascribed to due to homoantiaromaticity, of the type depicted for 41a. 

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