p-Toluenesulfonic acid → 1-Benzyloxy-4-(2-tetrahydropyran-2-yloxyethyl)benzene

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Reaction Steps

To a solution of 1-benzyloxy-4-(2-hydroxyethyl)benzene (7, 20 g, 87.7 mmoles) in CH2Cl2 (175 mL) was added 4-toluenesulfonic acid (TsOH, 0.17 g, 0.9 mmoles) and dihydropyran (9.9 mL dropwise, 108 mmoles). The mixture was stirred for 4 h and the solvent evaporated under reduced pressure to yield 28 g of crude product. This was purified by flash chromatography (solvent=70:30 ethyl acetate:heptane). The pure fractions were pooled and the solvent evaporated to give 1-benzyloxy-4-(2-tetrahydropyran-2-yloxyethyl)benzene (8, 26.5 g). NMR (CDCl3)δppm: 7.30(s, 5H); 6.97(q, 4H); 4.95(s, 2H); 7.87(s, 1H); 4.2-3.4(m, 4H); 2.8(t, 2H); 1.9-1.3(m, 6H). (Scheme II, Step 3.)

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