(CAS NO.: ), with its systematic name of 1H-Pyrrolizine-1-carboxylic acid, 2,3-dihydro-5-benzoyl-, (+-)-, could be produced through many synthetic methods.

Following is one of the reaction routes:

2-Methylthiopyrrole (I) is benzoylated with N,N-dimethylbenzamide (II) to produce 5-benzoyl-2-methylthiopyrrole (III) in the presence of POCl₃ in refluxing CH₂Cl₂, and the yielding product is condensed with spiro[2.5]-5,7-dioxa-6,6-dimethyloctane-4,8-dione (IV) in the presence of NaH in DMF giving compound (V). The oxidation of (V) with m-chloroperbenzoic acid in CH₂Cl₂ affords the sulfone (VI), which is submitted to methanolysis with methanol and HCl giving 1-(3,3-dimethoxycarbonylpropyl)-2-methanesulfonyl-5-benzoylpyrrole (VII). The cyclization of (VII) with NaH in DMF yields dimethyl 5-benzoyl-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1,1-dicarboxylate (VIII), which is finally hydrolyzed and decarboxylated with KOH in refluxing methanol.Compound (III) can be oxidized with m-chloroperbenzoic acid as before giving 2-methanesulfonyl-5-benzoylpyrrole (IX), which is then condensed with spiro compound (IV) as before to afford compound (VI), already obtained.