Comer titanium oxides

Pentadien-3-ol 7 is achiral. However, on complexation with the titanium catalyst and the chiral ligand, the two alkenes become non-equivalent (diastereotopic). The principles of kinetic resolution then come in to effect, with epoxidation of the aUcene such that the other alkene substituent does not obstruct the preferred face of oxidation (the lower face as drawn below, with the alcohol in the lower right comer using the (+)-tartrate ligand, model as in Scheme 5.60). Further epoxidation of 8 is slow using the (+)-tartrate ligand. See S. L. Schreiber, T. S. Schreiber and D. B. Smith, J. Am. Chem. Soc., 109 (1987), 1525. 

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