2-Methylbenzenesulfonic acid → 2H-Pyran, tetrahydro-2-(4-iodophenoxy)-

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a stirred solution of 4-iodophenol (11.0 g, 50 mmol) in CH2Cl2 (50 ml) cooled with an ice bath, dihydropyran (5.0 g, 60 mmol) was added dropwise over 10 min at 0–5° C. After the solution became clear, toluenesulfonic acid, TsOH, (10 mg) was added. The solution was stirred at 20° C. for 15 min. Then it was quenched by addition of NaHCO3 (1 g) and 3 drops of water, and after stirring for 5 min at 20° C., the solvent was removed in vacuo and the residue was purified by column chromatography on silica gel with petroleum ether as eluent to give 14.0 g (92%) of 1 as colorless crystal; mp 66° C.; δH(CDCl3; 300 MHz): 7.55(d, J=8.3, 2H, Ar—H), 6.83(d, J=8.4, 2H, Ar—H), 5.37(t, J=3.1, 1H, OCHO), 3.86(m, 1H, THP), 3.59(m, 1H, THP), 1.87˜1.58(m, 6H, THP).

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