Synthesis of enantiomerically pure (R)-and (S)-1-benzoyloxypropane-2,3-diol and revision of the stereochemical outcome of the Candida antarctica lipase-catalyzed benzoylation of glycerol

Enantiomerically pure (R)- and (S)-1-benzoyloxypropane-2,3-diol have been prepared from (S)-(+)-2,2-dimethyl-1,3-dioxolane-4-methanol and used as reference compounds to correct the reported stereochemical outcome of the Candida antarctica lipase (CAL)-catalyzed benzoylation of glycerol.

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(S)-1-Benzoyloxy-3-benzyloxy-2-propanolC17H18O4[α]D20=+6.1 (c 1, CHCl3)Source of chirality: (S)-(+)-2,2-dimethyl-1,3-dioxolane-4-methanolAbsolute configuration: (S)

(R)-1-Benzoyloxy-2,3-isopropylidene glycerolC13H16O4[α]D20=+14.8 (c 1, CHCl3)Source of chirality: (S)-(+)-2,2-dimethyl-1,3-dioxolane-4-methanolAbsolute configuration: (R)

(S)-1-Benzoyloxy-2,3-propanediolC10H12O4Ee >98%[α]D20=+15.8 (c 1, EtOH)[α]D20=+13.9 (c 1, pyridine)Source of chirality: (S)-(+)-2,2-dimethyl-1,3-dioxolane-4-methanolAbsolute configuration: (S)