Synthesis of (1R, 2S, 5S, 6R, 8S)-3-azabicyclo [3.3. 0] octane-2, 6, 8-tricarboxylic acid (2) from trans-4-hydroxy-L-proline (5) was attempted. A Diels–Alder reaction of 3, 4- dehydroproline derivative 9 and cyclopentadiene afforded a single stereoisomer 11. The Diels–Alder adduct was smoothly converted to the hydrochloride of 2 (24) via RuO 4 oxidation. Although some racemization of the material or product was observed during the ...
