title: Origins of stereoselectivities of dihydroxylations of cis-bicyclo[3.3.0]octenes.
abstract: Stereoselectivities 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.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Philipp
authors.initials: P
authors.lastname: Kohler
authors.forename: Larry E
authors.initials: LE
authors.lastname: Overman
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
mesh_terms: D001643:Bridged Bicyclo Compounds / Q000737:chemistry*; D006900:Hydroxylation; D008958:Models, Molecular; D013237:Stereoisomerism
chemical_list: D001643:Bridged Bicyclo Compounds