penicillanic acids penicillanic acid (2S,5R)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid 0 2,2-dimethylpenam-3alpha-carboxylic acid 201.046 201.24388 A penam that consists of 3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane bearing a carboxy group at position 2 and having (2S,5R)-configuration. Beilstein:4677775 C8H11NO3S CAS:87-53-6 CHEBI:37806 InChI=1S/C8H11NO3S/c1-8(2)6(7(11)12)9-4(10)3-5(9)13-8/h5-6H,3H2,1-2H3,(H,11,12)/t5-,6+/m1/s1 RBKMMJSQKNKNEV-RITPCOANSA-N Reaxys:4677775 [H][C@@]12CC(=O)N1[C@@H](C(O)=O)C(C)(C)S2 chebi_ontology penicillanic acid