[O:1]=[C:2]1[CH:7]=[CH:6][C:5]2[C:8](OS(C(F)(F)F)(=O)=O)=[CH:9][CH:10]=[CH:11][C:4]=2[O:3]1.[O:20]1[CH2:25][CH2:24][CH2:23][CH2:22][CH:21]1[O:26][CH2:27][CH2:28][CH2:29][CH2:30][C:31]#[CH:32].C(N(CC)CC)C.CN(C)C=O>CCOCC.O>[O:20]1[CH2:25][CH2:24][CH2:23][CH2:22][CH:21]1[O:26][CH2:27][CH2:28][CH2:29][CH2:30][C:31]#[C:32][C:8]1[C:5]2[CH:6]=[CH:7][C:2](=[O:1])[O:3][C:4]=2[CH:11]=[CH:10][CH:9]=1
A mixture of 1.47 g (5 mmol) of trifluoromethanesulfonic acid 2-oxo-2H-1-benzopyran-5-yl ester (preceding example), 1.0 g (5.5 mmol) of rac-6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexyne, 75 mg of cuprous iodide, 0.3 g (0.428 mmol) of dichloro-bis(triphenylphosphine)palladium(II), 7.5 mL of triethylamine, and 35 mL of dry N,N-dimethylformamide was stirred and heated at 100° C. for 24 hr. The reaction mixture was cooled, poured into water, and worked-up with ether in the usual manner. The dark-brown, oily residue was flash chromatographed on silica gel. Elution with 2:1 hexane-ethyl acetate gave 1.09 g (67%) of rac-5-[6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexynyl]-2H-1-benzopyran-2-one as an orange oil.
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