The enantioselective preparation of both enantiomers of a C 2 -symmetric diphenyl-bi-dihydropyran3 and 4 is described. The application of enantiopure bi-dihydropyrans 1 - 4 towards the simultaneous enantioselective differentiation and regioselective protection of a range of cyclic and acyclic symmetrical polyols (23, 37, 43, 45, 54, 61 and 66) is investigated. Several deprotections utilising trifluoroacetic acid (TFA) and a transketalisation with acidic glycerol are presented.