Dicyclopentadiene → 5-Norbornene-2-methanol hydroxylethyl ether

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a 300 mL autoclave equipped with a thermal couple and a mechanical stirrer, a mixture of 2-allyloxyethanol (109.5 g, 1.07 mol) and dicyclopentadiene (35.4 g, 0.27 mol) was stirred and heated to 190° C. The reaction was cooled after 3 h. Three such reactions were run and the reaction mixtures were combined. The mixture was distilled using a short-path distillation column under vacuum at 70° C. at 500 mTorr. The distillate (170 g) was dissolved in a mixture of 250 mL of CH3OH and 150 mL of H2O. Hexane (3×125 mL) was added to the mixture in order to extract out cyclopentadiene impurities. To the remaining methanol/water solution NaCl was added to force the product to oil out from solution. Ethyl acetate (200 mL) was added to extract the oil from water. After the solvents were removed by rotovaporation the product was dried under vacuum. Yield 157 g (58%). 1H NMR (500 MHz, CDCl3): Endo isomer: 6.13 (m, 1H); 5.93 (m, 1H); 3.72 (t, 2H); 3.52 (m, 2H); 3.22 (t, 1H); 3.10 (t, 1H); 2.90 (s, 1H); 2.80 (s, 1H); 2.37 (m, 1H); 2.09 (br s, 1H); 1.82 (m, 1H); 1.43 (d, 1H), 1.26 (d, 1H), 0.50 (d of t, 1H). Exo isomer: 6.10 (m, 1H); 6.07 (m, 1H); 3.75 (t, 2H); 3.36 (m, 2H); 3.50 (t, 1H); 3.40 (t, 1H); 2.80 (s, 1H); 2.74 (s, 1H); 2.09 (br s, 1H); 1.71 (m, 1H); 1.33 (d, 1H), 1.30 (d, 1H); 1.24 (m, partially obscured by endo isomer, 1H); 1.11 (d of t, 1H). Endo/exo ratio by 1H NMR was determined to be 82/18.

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