GENERAL STEPS: To a stirred mixture of tert-butyl 2-bromoacetate (5.4 mL, 36.6 mmol) and 2,2'-((oxo-bis(ethane-2,1-diyl))bis(oxy))diethanol (35.0 mL, 203 mmol) in DMSO (50 mL) was added in two additions of NaH (1.6217 g, 40.6 mmol, a 60% oil solution). The reaction mixture was slowly warmed to room temperature with continuous stirring for 23 hours. Subsequently, the reaction solution was diluted with water (50 mL), saturated with NaCl (50 g), stirred for 5 min and extracted with ether (3 x 100 mL). The organic phases were combined and concentrated. The residue was dissolved in dichloromethane (50 mL) and water (25 mL) and stirred for 5 minutes. The organic phases were separated by a phase separator, concentrated, and purified using an 80 g silica gel column with a gradient of ethyl acetate in hexanes as eluent (50-100%) to afford tert-butyl 14-hydroxy-3,6,9,12-tetraoxatetradecane-1-carboxylate (8.2 g, 72.7% yield) as a light yellow oil. rf = 0.08 (ethyl acetate). NMR hydrogen spectrum (400 MHz, CDCl3) δ 4.02 (d, J = 1.0 Hz, 2H), 3.75-3.60 (m, 12H), 1.47 (s, 9H) ppm. low-resolution mass spectrometry (ESI) m/z: C14H28O7 Calculated value: 308.3679; Measured value: 330.95 (M + Na)+; Measured value: 347.01 (M + K)+.