Transannular Electronic Interactions of 1,6-Cyclodecanedione Dioxime and its Synthesis

Chemistry Department, South Carolina State College. Orangeburg, South Carolina-29117
Manuscript received 14 July 1975; accepted 14 August 1975

An interesting ten-membered medium-sized ring compound, 1, 6-Cyclodecanedione dioxime is prepared, and its ultraviolet absorption spectra in 95% ethanol and concentrated sulfuric acid are studied. The compound exhibits unusual absorption bands at the wavelengths of 246 nm and 286 nm, and have the molar absorptivities of 13,200 and 16,800 liter mole^-1 cm^-1 in 95% ethanol and concentrated sulfuric acid respectively. The presence of a strong absorption band in the 246 nm region is taken as evidence for this transannular electronic interaction in the excited state.

The origin of π-π transition (K-band) and its assignment are discussed from the standpoint of the transannular electronic interaction (transannular conjugation)¹. This is an interesting conse­quence of the stereochemistry of the ten-membered ring.