tert-Butanol → 2,2,6,6-tetramethyltetrahydro-2H-pyran-4-carboxylic acid

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Reaction Conditions

Reaction Steps

To a solution of 2,2,6,6-tetramethyl-tetrahydro-pyran-4-one (3.00 g, 19.20 mmol), p-toluenesulfonylmethyl isocyanide (4.90 g, 24.96 mmol), and t-butanol (3.06 mL, 32.64 mmol) in 75 mL dimethoxyethane at 0° C. was added potassium t-butoxide (5.38 g, 48.01 mmol) at such a rate that the temperature did not increase above 10° C. After addition was complete the mixture was allow to attain RT and then heated at 35° C. overnight. The mixture was then cooled to RT and 50 mL of diethyl ether was added and the mixture was filtered. The filtrate was concentrated and redissolved in 50 mL of diethyl ether and filtered to remove the ppt. The filtrate was again concentrated and then dissolved in 50 mL of 2.25 M KOH and refluxed overnight. The mixture was cooled and washed with 2×50 mL of DCM. The pH of the aqueous layer was then adjusted to 2 with conc HCl and the product extracted with EtOAc (2×50 mL). The organic phase was dried over Na2SO4, filtered and concentrated to give 2.85 g (80%) of the title compound as an off-white solid which was used without further purification.

Provenance & Evidence