General method: 5.1.2 Synthesis of 7-methoxy-7-oxoheptanoic acid (84): a methanolic (150 ml) solution of KOH (5.87 g, 104.65 mmol) was slowly added dropwise to dimethyl heptanedioate (82, 16.94 g, 90 mmol) at 0 °C. The reaction mixture was stirred at room temperature for 4 hours. After completion of the reaction, the solvent was removed under reduced pressure and subsequently extracted by adding ether (100 ml) and water (200 ml). The organic phase was separated and concentrated to give yellow oil 82 (5.08 g, 30% yield). The aqueous phase was acidified to pH 3 with concentrated hydrochloric acid and extracted with ether (100 ml x 3). The combined organic layers were washed with brine (100 ml x 3), dried over magnesium sulfate and the solvent was concentrated under reduced pressure. The product was purified by silica gel column chromatography to give colorless oil 84 (5.96 g, 38% yield). Compound 85 was synthesized using the same method.5.1.2.1 Synthesis of 8-methoxy-8-oxooctanoic acid (85): 44% yield.ESI-MS m/z: 187.4 [M-H]-; 1H NMR (DMSO-d6) δ 1.21-1.32 (m, 4H), 1.43-1.53 (m, 4H), 2.18 (t, J=7.2 Hz, 2H), 2.29 (t, J=7.2Hz, 2H), 3.58 (s, 3H), 11.97 (s, 1H).
