3,4-dihydro-2H-pyran → HCID 18637143, compound

Reaction equation

[CH2:1]([O:8][CH2:9][C@H:10]1[C@H:15]([OH:16])[CH2:14][CH2:13][CH2:12][O:11]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[O:17]1[CH:22]=[CH:21][CH2:20][CH2:19][CH2:18]1.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>C(Cl)Cl>[CH2:1]([O:8][CH2:9][C@H:10]1[C@H:15]([O:16][CH:18]2[CH2:19][CH2:20][CH2:21][CH2:22][O:17]2)[CH2:14][CH2:13][CH2:12][O:11]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

Procedure

2.22 g of dl-trans-2-benzyloxymethyltetrahydropyran-3-ol (prepared as described in Preparation 2), 2.65 ml of dihydropyran and 0.05 g of pyridinium p-toluenesulfonate were dissolved in 40 ml of methylene chloride, and the mixture was stirred at room temperature for 4 hours. The solvent was then distilled off to give a residue, which was subjected to column chromatography through 80 g of silica gel. Those fractions eluted with mixtures of hexane and diethyl ether ranging from 6:1 to 5:1 by volume were worked up, to afford 2.93 g of the title compound as a colorless oil.