Synthesis
General procedure for the synthesis of 3-benzyloxy-cyclobutanecarboxylic acid from 3-benzyloxycyclobutane-1,1-dicarboxylic acid: 3-(benzyloxy)cyclobutane-1,1-dicarboxylic acid (1.5 g, 5.99 mmol) was dissolved in pyridine (3 mL) and the reaction was heated for 12 h at 120 °C in an oil bath. Upon completion of the reaction, the reaction mixture was cooled to room temperature and the pyridine was evaporated under reduced pressure. Subsequently, toluene (10 mL) was added to the residue and the resulting solution was washed with 1N hydrochloric acid solution (3 times), the organic phase was dried over anhydrous magnesium sulfate, filtered, and then concentrated under reduced pressure to give the brown oily target product 3-benzyloxy-cyclobutanecarboxylic acid (1.17 g, 95% yield).
References
[1] Patent: WO2011/143366, 2011, A1. Location in patent: Page/Page column 44
[2] Helvetica Chimica Acta, 1992, vol. 75, # 2, p. 589 - 603
[3] Collection of Czechoslovak Chemical Communications, 1982, vol. 47, # 9, p. 2440 - 2447
[4] Patent: WO2007/62332, 2007, A2. Location in patent: Page/Page column 17
[5] Patent: WO2007/62333, 2007, A2. Location in patent: Page/Page column 12