ja3075538_si_002.cif (16.31 kB)
Origins of Stereoselectivities of Dihydroxylations of cis-Bicyclo[3.3.0]octenes
dataset
posted on 2016-02-20, 10:39 authored by Hao Wang, Philipp Kohler, Larry E. Overman, K. N. HoukStereoselectivities of the dihydroxylations of cis-bicyclo[3.3.0]octene intermediates for a projected total
synthesis
of chromodorolide A have been explored experimentally. The reaction
occurs unexpectedly on the apparently more hindered (concave) face;
this result has been explained through computational studies using
B3LYP and B3LYP-D3 methods. Torsional effects are largely responsible
for the stereoselectivity encountered in the chromodorolide A synthesis.
Many literature examples have been reported on related cases. QM calculations
show that the stereoselectivities of dihydroxylations of fused cyclopentenes
are influenced by the conformational rigidity or flexibility of the
substrate. Torsional, electrostatic, and steric effects can all influence
stereoselectivity, and the rigidity or flexibility of conformations
of reactants provides a predictive guide to stereoselectivity.