2,2-Dimethyl-1,3-propanediol

• 2,2-Dimethyl-1,3-propanediol [D0791]
• p-Toluenesulfonic Acid Monohydrate (= p-TsOH·H₂O) [T0267]
• Furfural [F0073]
• Toluene

Furfural (1.66 mL, 20 mmol) was dissolved in toluene (30 mL) and then 2,2-dimethyl-1,3-propanediol (2.6 g, 25 mmol) and p-TsOH·H₂O (30 mg, 0.17 mmol) were added. A Dean-Stark apparatus was attached and the reaction mixture was stirred for 3 h at reflux temperature. After adding ethyl acetate (50 mL), the organic layer was washed with brine (30 mL). The organic layer was dried with anhydrous sodium sulfate and concentrated under reduced pressure. Purification of the crude product by silica gel chromatography (hexane:ethyl acetate = 10:1) afforded 1 (3.2 g, 88% yield) as a yellow oil.

The reaction solution was monitored by UPLC.

Compound 1

¹H NMR (400 MHz, CDCl₃); δ 7.45 (m, 1H), 6.46 (m, 1H), 6.37 (m, 1H,), 5.48 (s, 1H), 3.77 (d, J = 10.8 Hz, 2H), 3.64 (d, J = 10.6 Hz, 2H), 1.28 (s, 3H), 0.79 (s, 3H).

• Gold(i)-catalysed synthesis of conjugated trienes
• M. S. Hadfield, A.-L. Lee, Chem. Commun. 2011, 47, 1333.