Chemistry of Optically Active Cyanohydrins-Part 3:[1] Preparation and Reactions of (R)-2-Hydroxy-2-(naphthalen-1-yl)ethane- nitrile using (R)-Hydroxynitrile lyase from Prunus amygdalus. Antitumor and Antimicrobial Evaluation of the New Products

Abstract

CYANURATION of 1- naphthaldehyde (1) yielded the racemic …….2-hydroxy-2-(naphthalene-1-yl)ethanenitrile (R,S)-2 . The same reaction can be completed by using acetone cyanohydrin (3) as a transcyanating agent. The optically active cyanohydrin enantiomer (R)-2 could be obtained by hydrocyanation of (1) in presence of (R)-hydroxynitrile lyase (R)-Pa HNL [EC4.1.2.10] from almonds (Prunus amygdalus) as a chiral catalyst. Cyanohydrin 2 in its racemic and optically active forms reacts with the isocyanate reagents 4a-c to give the carbamate derivatives (R,S)-5 and (R)-5, respectively. On the other hand, the reaction of (R,S)-2 and (R)-2 with the isocyanate and/or isothiocyanate reagents 6a-e gave the 4-imino-2-oxazolidinone derivatives, (R,S)-8 and (R)-8, respectively. Moreover, derivatization of (R)-2 with (S)-Naproxen® chloride (S)-10 gave the respective diastereomer (R,2S)-11. The postulated structures for the new products were supported with compatible elementary microanalyses and spectroscopic (IR, 1H NMR, MS) measurements. The antitumor and antimicrobial activities of some selected racemic new products and their respective optically active analogues were also endeavored. The structure-activity relationship (SAR) was also discussed.

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