Opticalresolution of chiral buckybowls, C3 symmetric trimethylsumanene derivatives, was achieved by chiral HPLC. Enantiomeric excess (ee) of enatioselectively prepared trimethyltris(trimethylsilyl...
Asymmetric Synthesis of a Chiral Buckybowl, Trimethylsumanene
作者:Shuhei Higashibayashi、Hidehiro Sakurai
DOI:10.1021/ja802822k
日期:2008.7.1
The first asymmetric synthesis of a chiral buckybowl, a C(3) symmetric (C)-8,13,18-trimethylsumanene (1), was achieved by employing a synthetic strategy that translates chirality at sp(3) centers into bowl chirality. The synthesis features a syn selective cyclotrimerization of an enantiopure halonorbornene derivative, tandem ring-opening/closing olefin metathesis reactions, and DDQ oxidation at low temperature. The bowl-to-bowl inversion energy of 1 was determined as 21.6 kcal/mol by circular dichroism spectra measurement.