be used for prediction of the relative stereochemistry of structural motifs in
an intact form.’’123
A 1H NMR analysis method has been developed that leads to the assignment of
the stereochemistry ofb-hydroxy ketones, by visual inspection of theABXpatterns
for the (R)-methylene unit of the b-hydroxyketones.124 Since b-hydroxy ketones
are derived from the aldol reaction (see p. 1339), this new method is particularly
useful in organic synthesis. A method has also been developed that uses 13CNMR
to determine the relative stereochemistry of 2,3-dialkylpentenoic acids