2-chloro and 2-fluoro ketones derived from the chiral-pool

Both (2R,5R)- and (2S,SR)-isomers of 2-chloro-2-isopropyl-5-methyl-, 2-chlo ro-2-methyl-5-isopropyl- and 2-fluoro-2-methyl-5-isopropylcyclohexanones ha ve been synthesized and fully characterized. It is shown that a rapid overv iew of the H-1 NMR spectrum allows an unambiguous assignment of the axial o r equatorial position of the halogen atom and that the IR VCO absorption do es not differ from one isomer to the other. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.