Asymmetric synthesis of fluorinated cyclic beta-amino acid derivatives through cross metathesis.
The asymmetric synthesis of several fluorinated cis-2-aminocycloalkane carboxylic acids (cis-2-ACACs) with a cross metathesis (CM) reaction as the key step has been carried out, constituting the first time a metathesis protocol has been undertaken with fluorinated imidoyl chlorides. Subsequent chemoselective hydrogenation of the olefin moiety, Dieckmann condensation, and stereoselective reduction of the iminic double bond afforded the corresponding beta-amino esters with several ring sizes. The asymmetric version of the process was achieved by using (-)-8-phenylmenthol as a chiral auxiliary.