Tetrabutylammonium Fluoride → 3,4-Dihydro-5-hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid

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Reaction Steps

A solution of 1.0 g (1.75 mmol) of 5-[[(1,1-Dimethylethyl)-diphenylsilyl]oxy]-3,4-dihydro-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid in anhy. THF under argon was treated with 2.09 mL (2.09 mmol) of a 1M solution of tetrabutylammonium fluoride in THF (Aldrich). After stirring at RT for 1 hr the reaction was evaporated under reduced pressure and the residue subjected to column chromatography on flash-grade silica gel, eluting with 5% MeOH-CHCl3. The fractions containing product were combined and evaporated under reduced pressure to give 395 mg (67%) of 3,4-Dihydro-5-hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid as a tan-colored foam. MA: Calc for C20H30 O4.0.2H2O: C, 71.06; H, 9.06; O, 19.29. Found: C, 70.93; H, 8.95; O, 19.27.

Provenance & Evidence