Racemic 1,3-alkanediols (rac-1) undergo an enantioselective acetalization by treatment with l-menthone enol trimethylsilyl ether (10) in the presence of trifluoromethanesulfonic acid (10 mol%) to give thermodynamically less stable spiroacetal 3 (derived from 1) in preference to spiroacetal 4 (derived from ent-1). The kinetically controlled acetalization is applied to a novel kinetic resolution of racemic 1,3-alkanediols: Optically active diols ent-1 of 55-95 % ee are obtained when the racemic diols are allowed Lo react with 1.5 equiv of enol silyl ether 10 under similar conditions.