1.1: NaBH4 / tetrahydrofuran / 0.25 h / 0 °C 2.1: Et3N / toluene / 1.5 h / 0 °C 3.1: LiBr / dimethylformamide / 0.17 h / 20 °C 4.1: NaH / tetrahydrofuran; dimethylformamide / 1 h / 0 °C 4.2: 82 percent / tetrahydrofuran; dimethylformamide / 64 h / 20 °C 5.1: 85 percent / TsOH*H2O / CH2Cl2; methanol / 36 h / 40 °C View Scheme

KOC(CH3)3 in tetrahydrofuran (N2); KOC(CH3)3 in THF added slowly to a soln. of Cr complex, stirred for 1 h at room temp., C10H6(OCH2OCH3)C10H5(OCH2OCH3)CHO added, refluxed for 4 h; cooled at room temp., hydrolyzed with an aq. soln. of NH4Cl, extd. (CH2Cl2), the org. layers washed (H2O), dried (MgSO4), filtered, evapd. (vac.), chromd. (silica gel, petroleum ether/EtOAc); elem. anal.;