[C:1]([OH:3])#N.[O:4]1[CH:9]=[CH:8][CH2:7][CH2:6][CH2:5]1.[C:10]1(C)C=C[C:13](S(O)(=O)=O)=[CH:12][CH:11]=1.CC[O:23]CC>C(Cl)Cl>[O:4]1[CH2:5][CH2:6][CH2:7][CH2:8][CH:9]1[O:23][CH:13]1[CH2:12][CH2:11][CH2:10][CH2:1][O:3]1A solution of 1.23 g of Part A(6) cyano-alcohol (7.36 mmole) in 20 ml of dry methylene chloride was treated with 800 ml of dihydropyran (8.89 mmole) and catalytic amount of p-toluene sulfonic acid at 0°-5° C. After 4 hours, the reaction mixture was diluted with ether and washed with aqueous sodium bicarbonate solution. The aqueous layer was reextracted twice with ether. The combined organic extract was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The crude residue was chromatographed on a silica gel column and eluted with 20-25% ethyl acetate in hexane to obtain 1.61 g of title tetrahydropyranyl ether.
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