Synthesis of all four enantiomers of 1-aminoindane-2-carboxylic acid, a new cispentacin benzologue

Racemic cis- and trans-1-aminoindane-2-carboxylic acids (3 and 5) were prep ared from indene by chlorosulphonyl isocyanate addition followed by ring op ening and isomerisation. The intermediate racemic hydroxymethylated beta -l actam 6 was resolved through the lipase-catalysed asymmetric acylation of t he primary hydroxy group at the (R)-stereogenic centre. High enantioselecti vities (E>200) were observed when the enzymatic reactions were performed wi th lipase AK or lipase PS as catalyst and vinyl acetate or vinyl butyrate a s acyl donor. The hydrolysis and isomerisation resulted in all four enantio mers (9, 11, 13 and 14) of 1-aminoindane-2-carboxylic acid, a new benzologu e of cispentacin. (C) 2000 Elsevier Science Ltd. All rights reserved.