College of Agriculture and Life Sciences, Cornell University
Doi
Abstract
Oxidation
of 1,5-benzothiazepin-4-one (<b>5</b>-<b>A</b>)
stereoselectively afforded the <i>S</i>-oxide <b>8I</b>-<b>A</b> (a<i>S</i>,1<i>S</i>) in preference
to the diastereomer <b>8II</b>-<b>A</b> (a<i>S</i>,1<i>R</i>) affected by the remote
stereogenic axis. All the enantiomers (<b>8I</b>-<b>A</b>/<b>8I</b>-<b>B</b> and <b>8II</b>-<b>A</b>/<b>8II</b>-<b>B</b>) were separated and isolated, and
the interconversion between <b>8I</b> and <b>8II</b> (equilibrium
ratio ≈5:1) was unequivocally verified to be caused by the
rotation around the axis
