Title
Stereoselective synthesis of enantiomerically pure bowl-shaped hydroxytribenzotriquinacenes
Author
Philipp Rommelmann, Beate Nachtigall, Tim Guntelmann, Harald Gröger, Dietmar Kuck
Year
2018
Journal
Organic & Biomolecular Chemistry
Abstract
Enzyme-catalysed hydrolysis of the inherently chiral aryl acetate rac-11 bearing the bowl-shaped tribenzotriquinacene (TBTQ) core enables the stereoselective synthesis of the enantiomerically pure (M)-2-hydroxytribenzotriquinacene (M)-12. Starting from rac-11, for which two independent routes are described, the use of immobilised lipase CAL-A in buffered biphasic solution at pH 7 led to the TBTQ-phenol (M)-12 in 33% yield and with >99% ee on a preparative scale. Extended enzyme screening revealed that the use of CAL-B gives the same enantioselectivity. Furthermore, the chiroptical properties of the enantiomerically pure TBTQ-acetates (M)-11 and (P)-11, TBTQ-phenols (M)-12 and (P)-12 and the corresponding 2-hydroxy-3-iodotribenzotriquinacenes (M)-13 and (P)-13are reported.
Instrument
J-810
Keywords
Circular dichroism, Stereochemistry, Organic chemistry