Enantioselective synthesis of oxazolidinones: Amidine-based catalytic kinetic resolution

Identifier:  TFG:2551

Handle: https://hdl.handle.net/20.500.11797/TFG2551

Authors:  Fernández-Llamazares Aragón, Emma

Abstract:
The present project aims at developing new methodologies for the synthesis of enantioenriched sphingosine analogues. The proposed retrosynthetic pathway involved a sequential aziridination/ring-opening of dienyl carbamates followed by an organocatalysed kinetic resolution (KR) of the so obtained racemic oxazolidinones. Previous optimisation of the KR has demonstrated the key role of the exocyclic hydroxy protecting group, with the highest enantiocontrol obtained for benzoylated starting material due to cation-π interactions with the catalyst. In order to improve KR results, three different substrates bearing more electron-rich carbonyl groups such as carbonate and carbamate moieties were synthesised and subsequently tested. Thus, benzyl carbonate and diisopropyl carbamate rendered enantioenriched products in high selectivities similar to those obtained for benzoyl group whereas isopropyl carbonate proved to be slightly less effective.