3,4-dihydro-2H-pyran → methyl 2,2-dimethyl-3-(tetrahydro-2H-pyran-2-yloxy)propanoate

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Reaction Steps

To a stirred mixture of hydroxypivalic acid methyl ester (50.0 g, 378 mmol) and p-toluenesulfonic acid monohydrate (1.439 g, 7.57 mmol) in 250 mL of methyl-tert-butylether was added dihydropyran (48.1 mL, 568 mmol) slowly with cooling. The mixture was stirred at room temperature overnight, 50 mL of saturated NaHCO3 added and the mixture shaken and separated. The organic layer dried over MgSO4 and concentrated. Purification of the residue by flash chromatography using 330 g column, 0%-5% ethyl acetate in hexane gave methyl 2,2-dimethyl-3-(tetrahydro-2H-pyran-2-yloxy)propanoate as a clear oil: 1H NMR (400 MHz, CDCl3) δ 4.5 (s, 1H), 3.8-3.6 (m, 2H), 3.6 (m, 3H), 3.4 (s, 1H), 3.25 (m, 1H), 1.7 (m, 1H), 1.6-1.18 (m, 5H), 1.05 (m, 6H).

Provenance & Evidence