2-Hydroxymethyl-1,4-dioxane: synthesis, resolution and determination of the absolute configurations of the enantiomers.

2-Hydroxymethyl-1,4-dioxane 3 was resolved via salt formation between its hydrogen phthalate and (R)- or (S)-1-phenylethylamine, selective crystallization of the resultant diastereomeric mixtures and subsequent recovery of its enantiomers by saponification. The progress of the resolution was followed by chiral HPLC and the absolute stereochemistry of the two enantiomers determined by comparison of their specific rotations with that of (R)-3 synthesized from enantiomerically pure (R)-1-O-benzylglycerol. The results of the synthesis of 3 and of its resolution are discussed and compared with those previously obtained for 1,2-isopropylidene glycerol evaluating the consequences of replacement of ispropylidene with an ethylene bridge.