The assignment of syn (or anti)23
stereochemistry was made on the basis of the characteristic
resonance of the carbinol proton: in the case of the
syn isomer it was always shifted downfield compared to
that of the anti isomer (ä 5.01 vs 4.99 for 3i and 3j; 4.93
vs 4.85 for 3k and 3l, respectively), as reported and
demonstrated for similar epoxy alcohols derived from
styrene oxide.