ИСТИНА

Recently the synthesis of organofluorine compounds has attracted explosive interest due to their anomalous physical properties and high physiological activity. Optically active fluorinated alcohols are important building blocks or end-products in organic synthesis and steric and electronic effects of fluorine in ketones play a vital role in their reactions. We developed the synthesis of chiral fluorinated aminoalcohols and aminoketone from (S)-N,N-dimethyl-1-phenethylamine via its ortho-lithiation followed by condensation with fluoroketones and esters of fluoroacids. Unexpectedly in the reaction of 1a with esters of fluoroacids we obtained not the objective ketone (with CF3COOEt) but its reduction product 3a. The reaction may be considered as “domino-reaction” – the ketone , formed at the first step, or its internal hemi-aminal is reduced by the hydride-ion from lithium ethoxide. The reduction is believed to follow a six-membered transition state. The only ketone was received when there is no hydrogen in the using ester (CF3COOPh). The second product of the reduction step of the reaction - aldehyde (benzaldehyde) was obtained in the condensation of 1a with CF3COOCH2Ph. The stereoselectivity of the reactions was determined by 1H NMR spectroscopy (de 50% and 100%). The configuration of the new chiral (carbinol) center was established by X-Ray analysis.