Acetic Acid → (4R,6R)-6-{2-[(1S,2S,6S,8S,8aR)-1,2,6,7,8,8a-Hexahydro-6-hydroxy-8-(2-ethyl-2-methylbutyryloxy)-2-methyl-1-naphthyl]ethyl}tetrahydro-4-hydroxy-2H-pyran-2-one

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Reaction Steps

A solution of 600 mg (0.9 mmol) of (4R,6R)-6-{2-[(1S,2S,6S,8S,8aR)-1,2,6,7,8,8a-hexahydro-6-t-butyldimethylsilyloxy-8-(2-ethyl-2-methylbutyryloxy)-2-methyl-1-naphthyl]ethyl}tetrahydro-4-t-butyldimethylsilyloxy-2H-pyran-2-one [prepared as described in Example 5, above] in 2 ml of tetrahydrofuran was added to a mixture of 12.7 ml of a 1M tetrahydrofuran solution of tetrabutylammonium fluoride and 1.27 ml of acetic acid, and the resulting mixture was stirred at room temperature for 15 hours. At the end of this time, the tetrahydrofuran was removed from the reaction mixture by distillation under reduced pressure. The residue was then diluted with 50 ml of ethyl acetate and the diluted solution was washed twice with 50 ml each time of water, three times with 30 ml each time of a saturated aqueous solution of sodium hydrogencarbonate and once with a saturated aqueous solution of sodium chloride, in that order. The organic layer was then dried over anhydrous magnesium sulfate and removed from the mixture by filtration, after which the solvent was removed by distillation under reduced pressure. The residue was purified by flash column chromatography through silica gel, using ethyl acetate as the eluent, to give 387 mg (98% yield) of the title compound as a colorless solid. This compound was recrystallized from a mixture of hexane and ethyl acetate to produce the title compound as colorless prisms, melting at between 152° and 154° C.

Provenance & Evidence