Enantioselective synthesis of amino acids from pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione

Treatment of (+)-pentacyclo[5.4.0.0(2.6).0(3.10).0(5.9)]undecane-8-one with sodium cyanide and ammonium carbonate produced an optically active hydantoin of which the 4'-carbonyl group of the hydantoin ring is in the less sterically hindered equatorial position. Hydrolysis of the latter with barium hydroxide produced (-)-8-amino-pentacyclo[5.4.0.0(2.6).0(3.10).0(5.9)]undecane-8-carboxylic acid which has the 1S,2R.3R,5R,6R,7S,8R,9R,10R configuration. In a similar way. (+)-6-amino-tetracyclo-[6.2.0.0(4.11).0(5.9)]undec-2-ene-6-carboxylic acid with 1R.4R.5R.6R.8S.9S.11R configuration was obtained from (-)-tetracyclo[6.3.0.0(4.11).0(5.9)]undec-2-ene-6-one. The latter was obtained from (-)-11-hydroxy-pentacyclo[5.4.0.0(2.6).0(3.10).0(5.9)]undecane-8-one. (C) 2001 Elsevier Science Ltd. All rights reserved.