Configuration-Dependent Medium-Sized Ring Formation: Chiral Molecular Framework with Three- Dimensional Architecture

SONA KRAJCOVICOVA; NADEZDA CANKAROVA; AGUSTINA LA VENIA; VIKTOR KRCHNAK

JOURNAL OF ORGANIC CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2018

0022-3263

Thiscommunication describes a configuration-dependent [6+8+5] fused ring formation via a tandem cyclic N-acyliminium-nucleophilic additionreaction. Cyclizationof theacyclic precursor prepared on the solid phase using L-Ser and racemic mixture of Fmoc-trans-2-aminocyclohexane carboxylic acidpredominantlyyielded the cyclic diastereomer with the (1R,2R)-2-aminocyclohexanemoiety rather than the tricyclic diastereomer from the (1S,2S)-enantiomer. Incontrast,the model compound prepared with D-Ser predominantly cyclized with the(1S,2S)-2-aminocyclohexane carboxylic acid substrate. Theoutcome of the cyclization was not influenced by the type of resin, the spacer orthe N-substituent. The analogoussynthesis of the [6+7+5] fused ring system yielded an inseparable diastereomersin a 1:0.6 ratio.