A tandem reaction sequence consisting of platinum-catalyzed diboration of 1,3-dienes
followed by intramolecular allylboration and oxidative hydrolysis has been developed
for constructing cyclic structures that bear a 1,3-diol. This methodology has proven
effective for synthesizing cyclohexanes from dienals in good yields (44-64%) to generate
diols containing two new vicinal stereocenters, one of which is quaternary. The products
are obtained in high regio- and diastereomeric ratios (>19:1). A preexisting stereocenter
on the substrate can provide high levels of asymmetric induction in the product.
diboration - diene - platinum - allylboration - quaternary stereocenter