(1S,3aR,6aS)-Hexahydro-cyclopenta[c]pyrrole-1,2(1H)-dicarboxylic Acid 2-(tert-Butyl) Ester synthesis

Yield:597569-42-1 72%

Reaction Conditions:

Stage #1: (1S,3aR,6aS)-hexahydro-cyclopenta[c]pyrrole-1,2-dicarboxylic acid 2-tert-butyl ester ethyl esterwith ethanol;sodium hydroxide at 20; for 3 h;
Stage #2: with hydrogenchloride in water;

Steps:

1.8

Step 8. Preparation of (1S,3aR,6aS)-2-BOC-octahydrocyclopenta[c]pyrrole-1-carboxylic acid (Compound 11)Compound 10 (13 g, 46 mmol) is treated with 2N NaOH (44 ml) in EtOH (120 ml) at rt for 3 hr. Volatiles are evaporated and the residue is dissolved in water (50 ml). 1N HCl is added to adjust pH to and the aqueous solution is back extracted with DCM (100 ml×3). The DCM is evaporated to give compound 11 (8.5 g, 72%) as colorless syrup.

References:

US2010/292219,2010,A1 Location in patent:Page/Page column 17