Conformational energy and entropy differences of the t-butoxy group and implications in stereochemistry and stereoelectronics

The conformational energy and entropy differences of the t-butoxy group were determined using 1H- and 13C-NMR variable temperature techniques and ΔEconf was calculated by molecular mechanics (MM2). Strikingly small values were observed and discussed in conjunction with the alleviated anomeric effect in 2-t-butoxytetrahydropyran systems.