Acetic Anhydride → 9-Acetoxy-4,4-dimethyl-7-(1,2-dimethylheptyl)-1,2,3,4-tetrahydrocyclopenta[c][l] benzopyran

関与物質

反応手順

A solution of 4,4-dimethyl-9-hydroxy-7-(1,2-dimethylheptyl)-1,2,3,4-tetrahydrocyclopenta[ c][l]benzopyran (6.85 g., 0.02 mole) and acetic anhydride (3.06 g., 0.03 mole) in 20 ml. of pyridine was warmed over a steam bath with stirring for 2 hours. The reaction mixture was allowed to cool to room temperature and the pyridine was removed by evaporation under reduced pressure. Water was added to the residue and this aqueous mixture was extracted with three portions of ether. The ether extracts were washed several times with water, 6N HCl, again with water, and dried over Na2SO4. Solvent evaporation in vacuo left 7.59 g. (99%) of crude acetate. The ir and nmr were in agreement with the proposed structure.

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