28114-87-6

64775-97-9

28114-87-6

The general procedure for the synthesis of spiro[3.3]heptane-2,2-dicarboxylic acid from spiro[3.3]heptane-2,2-dicarboxylic acid was as follows: spiro[3.3]heptane-2,2-dicarboxylic acid (1.737 g, 9.43 mmol) was dissolved in pyridine (20 mL) and the reaction was heated at 115 °C overnight. Upon completion of the reaction, the mixture was cooled to room temperature and concentrated to dryness in a rotary evaporator. The resulting residue was treated with 6 M aqueous hydrochloric acid and subsequently extracted with dichloromethane (3 x 20 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered and concentrated to dryness to afford spiro[3.3]heptane-2-carboxylic acid (1.21 g, 92% yield). The product was characterized by 1H NMR (400 MHz, DMSO-d6): δ 11.98 (s, 1H), 2.85 (m, 1H), 2.15-2.03 (m, 4H), 1.96 (t, J = 7.3 Hz, 2H), 1.84 (t, J = 7.3 Hz, 2H), 1.76-1.70 (m, 2H).