10.1007/BF00962755
The study investigates the fluorodeoxygenation of (R,S)- and (S)-proline using sulfur tetrafluoride in hydrogen fluoride to produce =-trifluoromethylpyrrolidine (-)-(I), aiming to explore the retention of optical activity and absolute configuration of the chiral =-carbon atom during this process. The authors obtained diastereomeric derivatives such as (+)-(IIA) to determine the optical purity of (-)-(I), which was found to be no less than 96%. The study also examines the stereochemistry of chromophoric derivatives like the nitrosoamine (+)-(III) and the chloroamine (-)-(IV), comparing their chiroptical characteristics with those of analogs such as l-nitroso-(S)-proline methyl ester (V) and l-chloro-(S)-proline methyl ester (VI). The results indicate that the absolute (S) configuration of the carbon chiral center is preserved during the fluorodeoxygenation of (S)-proline.