Reaction Steps
For (Z)-2-(3-Carboethoxyphenyl)-5-[3-(1-adamantyl)-4-methoxyphenyl]-2-pentenol (8j). A ~1:1 mixture of 7j (3:1, Z:E) and 1-(t-butyldimethylsiloxy)-2-phenyl-5-[3-(1-adamantyl)-4-t-butyldimethylsiloxyphenyl]-2-pentene (3:1, Z:E) (1.6 g) was dissolved in 30 mL of 3:1:1 acetic acid/THF/H2O, and stirred for 48 h. The solvent was removed in vacuo. The residue was purified by column chromatography on silica gel (elution with methylene chloride to 5% methanol/methylene chloride) to give 0.490 g of pure (Z)-2-(3-carboethoxyphenyl)-5-[3-(1-adamantyl)-4-t-butyldimethylsiloxyphenyl]-2-pentenol (74% based on ca. 800 mg of 7j in the starting mixture): 1H NMR (300 MHz, CDCl3) δ7.96 (dt, J=8, 1 Hz, 1H, 2-ArH), 7.89 (t, J=1 Hz, 1H, 2-ArH), 7.38 (t, J=8 Hz, 1H, 2-ArH), 7.22 (m, 1H, 2-ArH), 6.91 (d, J=2 Hz, 1H, 5-ArH), 6.77 (dd, J=2, 8 Hz, 1H, 5- ArH), 6.63 (d, J=8 Hz, 1H, 5-ArH), 5.82 (t, J=8 Hz, 1H, C=CH), 4.23-4.40 (m, 4H, CH2OH and CO2CH2CH3), 2.59 (t, J= 8 Hz, 2H, ArCH2), 2.26 (q, J=8 Hz, 2H, ArCH2CH2), 2.08 (s, 9H, adamantyl), 1.76 (s, 6H, adamantyl), 1.39 (t, J=8 Hz, 3H, CO2CH2CH3), 1.01 (s, 9H, SiC(CH3)3), and 0.31 (s, 6H, Si(CH3)2). (Z)-2-(3-Carboethoxyphenyl)-5-[3-(1-adamantyl)-4-t-butyldimethylsiloxyphenyl]-2-pentenol (490 mg) was converted in two steps to 8j via treatment with tetrabutylammonium fluoride and then alkylation with dimethyl sulfate as described in the synthesis of 5×. Purification of 8j by column chromatography on silica gel (elution with 30% ethyl acetate/hexane) gave 0.150 g of pure 8j (37% for two steps): 1H NMR (300 MHz, CDCl3) δ7.96 (dt, J=1, 8 Hz, 1H, 2-ArH), 7.89 (t, J=1 Hz, 1H, 2-ArH), 7.39 (t, J=8 Hz, 1H, 2-ArH), 7.28 (m, 1H, 2-ArH), 6.92 (d, J=2 Hz, 1H, 5-ArH), 6.89 (dd, J=2, 8 Hz, 1H, 5- ArH), 6.76 (d, J=8 Hz, 1H, 5-ArH), 5.83 (t, J=8 Hz, 1H, C=CH), 4.33-4.42 (m, 4H, CH2OH and CO2CH2CH3), 3.80 (s, 3H, OCH3), 2.61 (t, J=8 Hz, 2H, ArCH2), 2.29 (q, J=8 Hz, 2H, ArCH2CH2), 2.06 (s, 9H, adamantyl), 1.76 (s, 6H, adamantyl), and 1.40 (t, J=8 Hz, 3H, CO2CH2CH3).
