Abstract The MαNP acid method is very powerful for the preparation of enantiopure alcohols by resolution and the simultaneous determination of their absolute configurations by the 1 H NMR anisotropy effect, where the syn-syn conformation is taken as the preferred conformation of MαNP esters. However, the syn-syn conformation of MαNP esters looks unstable, because two electronegative oxygen atoms (CH 3 O and C= O) are close to ...