Hydrochloric Acid → Hydroxy-PEG4-t-butyl ester

Participants

Reaction Steps

To 300 mL of anhydrous THF was added 80 mg (0.0025 mol) of sodium metal and 128 mL of tetraethylene glycol 4a (0.94 mol) with stirring (Seitz and Kunz, J. Org. Chem., 62:813-826 (1997)). After the sodium had completely dissolved, tert-butyl acrylate (24 mL, 0.33 mol) was added. The solution was stirred for 20 hrs at room temperature and neutralized with 8 mL of 1.0 M HCl. The solvent was removed in vacuo and the residue was suspended in brine (250 mL) and extracted with ethyl acetate (3×125 mL). The combined organic layers were washed with brine (100 mL) then water (100 mL), dried over sodium sulfate, and the solvent was removed. The resulting colorless oil was dried under vacuum to give 77.13 g (73% yield) of product 9a (FIG. 7). 1H NMR: 1.40 (s, 9H), 2.49 (t, 2H, J=6.4 Hz), 3.59-3.73 (m, 18H).

Provenance & Evidence