Optical Resolution of 5-Alkyl-δ-Valerolactones and Synthesis of Optically Active 5-Fluoroalkanols
摘要:
Optical resolutions of 5-alkyl-delta-valerolactones were carried out by derivatization to the diastereomeric amides, in which (R)-(+)1-(1-naphthyl)ethylamine or (S)-(-)-1-phenylethylamine were used as resolving agents. Optically active 5-fluoroalkanols, useful intermediates for fluorinated ferroelectric liquid crystals, were derived from the resolved lactones in four steps without racemization.
Optical Resolution of 5-Alkyl-δ-Valerolactones and Synthesis of Optically Active 5-Fluoroalkanols
摘要:
Optical resolutions of 5-alkyl-delta-valerolactones were carried out by derivatization to the diastereomeric amides, in which (R)-(+)1-(1-naphthyl)ethylamine or (S)-(-)-1-phenylethylamine were used as resolving agents. Optically active 5-fluoroalkanols, useful intermediates for fluorinated ferroelectric liquid crystals, were derived from the resolved lactones in four steps without racemization.
A highly efficient method for kineticresolution of racemic aliphatic alcohols without conversion of the hydroxyl group has been realized; the method involves hydrogenation mediated by a remote ester group and is catalyzed by a chiral iridium complex. This powerful, environmentally friendly method provides chiral δ-alkyl-δ-hydroxy esters and δ-alkyl-1,5-diols in good yields with high enantioselectivities
A new general method for synthesizing N-benzyl-2-alkylpyrrolidines and N-benzyl-2-alkylpiperidines, having very high enantiomeric excess, has been achieved starting from aldehydes and organoborane reagents.