Polyfluorobicyclo[2.2.1]heptanes. Part 11. Bridgehead radicals: their generation, reactions, and CIDNP effects

Abstract

Decomposition of bis-(4H-decafluorobicyclo[2.2.1]heptane-1-carbonyl) peroxide (I) alone affords 4H-decafluorobicyclo[2.2.1]heptan-1-yl 4H-decafluorobicyclo[2.2.1]heptane-1-carboxylate (III) and 4H,4H′-eicosafluoro-1,1′-bis(bicyclo[2.2.1]heptyl)(IV). In hexachloroacetone the peroxide (I) yields (IV) and 4H-1-chlorodecafluorobicyclo[2.2.1]heptane (V). Decomposition of (I) at 185° in hexachloroacetone in an n.m.r. probe showed large CIDNP effects. The decarbonylation of 4H-decafluorobicyclo[2.2.1]heptane-1-carbaldehyde (VI) by di-t-butyl peroxide yielded 1H,4H-decafluorobicyclo[2.2.1]heptane (VII). Electrolysis of 4H-decafluorobicyclo[2.2.1]heptane-1-carboxylic acid in the presence of methyl propenoate gave (E)-1-(4H-decafluorobicyclo[2.2.1]heptan-1-yl)-2-methoxycarbonylethylene (VIII), 1-(4H-decafluorobicyclo[2.2.1]heptan-1-yl)-2-methoxycarbonylethane (IX), and (±)- and meso-1,4-bis-(4H-decafluorobicyclo[2.2.1]heptan-1-yl)-2,3-bismethoxycarbonylbutanes (X) and (XI).