1 TSA 8-hydroxy-2-oxa-bicyclo[3.3.1]non-6-ene-3,5-dicarboxylic acid 1.000 2 0GZ 2-oxo-2h-pyran-4,6-dicarboxylic acid 0.706 3 PRJ (2s,3as,6r,7as)-6-hydroxyoctahydro-1h-indole-2-carboxylic acid 0.706