Chirality transmission in flexible 5,5′-dinitrodiphenic esters connected with chiral secondary alcohols

Induced circular dichroism (CD) was observed with dinitrodiphenic esters of chiral secondary alcohols. The CD spectra of the esters prepared from a pair of antipodal alcohols were symmetrical to each other relative to the x-axis, indicating the enantiomeric nature of the esters. The sign of the Cotton effect at around 270 nm was found to reflect the absolute configuration of the original alcohol. In the case of aliphatic mono-alcohols, negative Cotton effect was observed for the esters of (R)-alcohols and a positive effect for the esters of (S)-alcohols. On the contrary, unsaturation or an oxygen atom at the vicinal position reversed the sign of the Cotton effect.