D with brine, dried more than MgSO4, and filtered. The filtrate was concentrated and purified by flash column chromatography (SiO2, 7 g, 25 EtOAc/ hexanes) to offer the terminal acetylene 23 as a white strong (0.092 g, 68 yield): TLC Rf = 0.1 (25 EtOAc/hexanes); mp 113.6-115.three ; 1H NMR (500 MHz, CDCl3) 7.61 (d, J = 7.eight Hz, 1H), 7.56 (d, J = eight.5 Hz, 2H), 7.19 (d, J = eight.five Hz, 2H), 7.15 (dd, J = 7.8, 1.four Hz, 1H), 7.01 (d, J = 1.7 Hz, 1H), four.21 (qd, J = 7.0, two.3 Hz, 1H), three.88 (s, 3H), 2.23 (d, J = 2.four Hz, 1H), 1.47 (d, J = 7.0 Hz, 3H); 13C NMR (125 MHz, CDCl3) 189.two, 156.4, 155.six, 150.three, 140.6, 138.9, 133.1, 130.3, 128.three, 128.two, 122.1, 119.7, 109.six, 87.7, 69.six, 60.6, 55.7, 25.3, 22.eight, 21.2, 14.4; IR (neat cm-1) 3423, 3308, 3268, 3199, 2969, 2341, 2105, 1698, 1606, 1494, 1378, 1213, 586; HRMS (DART, M+ + H) m/z 296.1300 (calculated for C18H18NO3, 296.1287). 3-Methoxy-4-(1-methyl-prop-2-ynyl)-biphenyl-4-carboxylic Acid Methyl Ester (24). According to the common process for homologation, methoxymethyl triphenylphosphonium chloride (1.05 g, 3.06 mmol) in dry THF (9 mL), NaOtBu (0.367 g, three.9 mmol), and ketone 14 (0.434 g, 1.59 mmol) in THF (three mL) have been stirred at 0 . Following the general workup, the mixture of enol ethers (0.214 g, 0.69 mmol) in THF/H2O (9:1, 5 mL) was hydrolyzed making use of Hg(OAc)2 (0.656 g, 2.1 mmol) at space Drug Metabolite Chemical Synonyms temperature. Right after the common extraction process, aldehyde (0.194 g, 0.65 mmol) in MeOH (three mL), the Ohira-Bestmann reagent (0.224 g, 1.17 mmol) dissolved in MeOH (2 mL), and powdered K2CO3 (0.188 g, 1.36 mmol) had been stirred at 0 . Following the common workup and flash chromatography (SiO2, 7 g, 2 EtOAc/hexanes), alkyne 24 was obtained as a white strong (0.111 g, 25 yield over three steps); TLC Rf = 0.3 (five EtOAc/hexanes); mp 106-108.five ; 1H NMR (500 MHz, CDCl3) eight.09 (d, J = 8.1 Hz, 2H), 7.72-7.57 (m, 3H), 7.20 (d, J = 7.7 Hz, 1H), 7.06 (s, 1H), 4.21 (q, J = 5.0 Hz, 1H), 3.92 (s, 3H), 3.90 (s, 3H), two.23 (d, J = two.0 Hz, 1H), 1.47 (d, J = 7.0 Hz, 3H); 13C NMR (125 MHz, CDCl3) 167.1, 156.five, 145.eight, 140.1, 131.3, 130.two, 129.1, 128.4, 127.2, 119.9, 109.5, 87.5, 69.7, 55.7, 52.three, 25.4, 22.eight; IR (neat cm-1)3255, 2970, 2950, 2929, 2108, 1698, 1605, 1430, 1393, 1104, 1281, 769, 676; HRMS (DART, M+ + H) m/z 295.1329 (calculated for C19H19O3, 295.1334). 3-Methoxy-4-(1-methyl-prop-2-ynyl)-biphenyl-4-yl)-Camptothecins medchemexpress dimethylamine (25). Based on the general procedure for homologation, methoxymethyl triphenylphosphonium chloride (0.67 g, 1.95 mmol) in dry THF (10 mL), NaOtBu (0.22 g, 2.34 mmol), and ketone (0.21 g, 0.78 mmol) in THF (3 mL) had been stirred at 0 . Following the common workup, the mixture of enol ethers (0.18 g, 0.62 mmol) in THF/H2O (9:1, 10 mL) was hydrolyzed utilizing Hg(OAc)two (0.30 g, 0.93 mmol) at area temperature. Following the common extraction process, aldehyde (0.17 g, 0.62 mmol) in dry MeOH (6 mL), theArticleOhira-Bestmann reagent (0.36 g, 1.86 mmol) dissolved in MeOH (two mL), and powdered K2CO3 (0.26 g, 1.86 mmol) were stirred at 0 . Following the basic workup and flash chromatography (SiO2, 10g, 15 EtOAc/hexanes), alkyne 25 was obtained as a white strong (0.015 g, 6 yield over 3 steps); TLC Rf = 0.52 (10 EtOAc/hexanes); mp 60.8- 61.1 ; 1H NMR (500 MHz, chloroform-d) 7.56 (d, J = 7.9 Hz, 1H), 7.48 (d, J = 8.9 Hz, 2H), 7.14 (dd, J = 7.9, 1.7 Hz, 1H), 7.01 (d, J = 1.six Hz, 1H), 6.79 (d, J = eight.7 Hz, 2H), four.18 (qd, J = 7.1, two.six Hz, 2H), 3.88 (s, 3H), 2.98 (s, 6H), two.20 (d, J = two.five Hz, 1H), 1.46 (d, J = 7.1 Hz, 3H); 13C NMR (12.