Hydrochloric Acid → 5-{[2-Tert-butyl-4-(2-hydroxyethoxy)-5-methylphenyl]sulfanyl}-6-hydroxy-2-[4-(2-hydroxyethoxy)phenyl]-2-(2-phenylethyl)-2,3-dihydro-4h-pyran-4-one

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Reaction Steps

To a round bottom flask equipped with a magnetic stirrer were added 6-{4-[2-(tert-butyl-dimethyl-silanyloxy)-ethoxy]-phenyl}-4-hydroxy-6-phenethyl-5,6-dihydro-pyran-2-one (prepared in Example SS; 0.260 g, 0.555 mmol), toluene-4-thiosulfonic acid S-{2-tert-butyl-4-[2-(tert-butyl-dimethyl-silanyloxy)-ethoxy]-5-methyl-phenyl} ester (prepared in Example PPP; 0.282 g, 0.555 mmol), K2CO3 (0.346 g, 2.50 mmol), and DMF (5 mL), as described in General Method 9. The mixture was stirred at room temperature for 2 days at which time MeOH (150 mL) was added and the solution taken to pH 3.0 with conc. HCl . The reaction was quenched with H2O (500 mL) and extracted with EtOAc. The organics were dried over MgSO4 and concentrated; the residue was taken up in a small amount of EtOAc and triturated with hexane. The solid was filtered and dried under high vacuum to yield the title compound, m.p. >190° C. (dec.). 1H NMR (DMSO-d6) δ 1.45 (s, 9 H), 1.68 (s, 3 H), 2.22 (br m, 4 H), 2.51 (br m, partially obscured by DMSO, 2 H), 3.34 (d of ABX q, partially obscured by H2O, 1 H), 3.40 (d of ABX q, partially obscured by H2O, 1 H), 3.67 (br m, 2 H), 3.72 (br m, 2 H), 3.91 (t, 2 H), 3.98 (t, 2 H), 6.76 (s, 1 H), 6.96 (s, 1 H), 6.99 (d, 2 H), 7.08-7.22 (m, 1 H), 7.10 (d, 2 H), 7.24 (d, 2 H), 7.30 (d, 2 H).

Provenance & Evidence