Ixture was stirred for 3 min. The mixture was then filtered plus the resin was washed with MeOH (40 mL). The solvent was evaporated, the residue was dispersed in benzene and freeze-dried to offer compound six (1.695 g, 90.5 ) as colorless oil. IR (neat): 3180 br m, 1736vs, 1220s, 1104s, 1069s, 837m cm-1; 1H NMR (CDCl3, 200 MHz) 1.32 (s, 3H), 1.42 (s, 3 H), four.04?.12 (dd, 1H, J = eight.7, 5.1 Hz), four.16?.24 (dd, 1H, J = 7.3, eight.7 Hz), four.51?.57 (dd, 1H, J = 5.1, 7.three Hz), 9.45 (s, 1H); 13C NMR (CDCl3, 50 MHz) 25.two, 25.7, 67.1, 73.five, 111.7, 175.eight; []D20 -25.two?(c 1.1, CHCl3), known compound. (ii) Dodecyl-2,2-dimethyl-1,3-dioxolane-4-carboxylate (7a): To a option of compound six (1.6213 g, 11.1 mmol) in 35 mL of CHCl3 were added 12-dodecanol (two.2920 g, 12.3 mmol), DMAP (1.5027 g, 12.3 mmol), and DCC (two.5379 g, 12.3 mmol) and the mixture was stirred for 7 h. The DCC-urea that formed was filtered off, and also the solvent was evaporated. TheNIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptTetrahedron. Author manuscript; obtainable in PMC 2015 Might 13.Rosseto and HajduPageresidue was dissolved in CH2Cl2 and purified on a silica gel column packed and eluted with CH2Cl2. The fractions containing the solution have been combined, evaporated, dissolved in benzene and freeze-dried to provide 7a (two.8202 g, 76.four ) as colorless wax. IR (CHCl3): 1740 br cm-1; 1H NMR (CDCl3, 200 MHz) 0.86 (br t, 3H), 1.24 (br s, 18H), 1.39 (s, 3H), 1.48 (s, 3H), 1.64 (m, 2H), 4.18 (m, 4H), four.56 (t, 1H, J = 6.two Hz). 13C NMR (CDCl3, 50 MHz) 14.2, 22.eight, 25.7, 25.9, 26.0, 28.7, 29.three, 29.5, 29.six, 29.7, 29.7, 32.0, 65.6, 67.5, 74.3, 111.4, 171.4. Rf (CH2Cl2) 0.69. []D20 -10.4?(c 1.02, CHCl3/MeOH four:1), known compound. (iii) 12-[(4-methyl-2-oxo-2H-chromen-7-yl)thio]dodecyl-2,2-dimethyl-1,3-dioxolane- 4carboxylate (7b): To a option of six (0.400 g, 2.7 mmol) in 25 mLCHCl3 had been added 7[(12-hydroxydodecyl)thio]-4-methyl-2H-chromen-2-one (0.8010 g, two.1 mmol), DMAP (0.2598 g, 2.1 mmol) and DCC (0.5614 g, 2.1 mmol). The mixture was stirred for six h, then the DCC-urea that formed was filtered along with the solvent was evaporated. The residue was redissolved in CHCl3 and purified on a silica gel column packed with CHCl3 and eluted with CHCl3:EtOAc (20:1). The fractions containing the item were combined, evaporated, dissolved in benzene and freeze-dried to give 7b (0.9342 g, 88.two ) as a white solid. IR (CHCl3): 3257, 1732 br, 1621, 1246 cm-1; 1 H NMR (CDCl3, 200 MHz) 1.17 (br s, 16H), 1.30 (s, 3H), 1.39 (s, 3H), 1.56 (m, 4H), 2.28 (s, 3H), two.87 (t, 2H, J = 7.two Hz), four.05 (m, 4H), four.48 (t, 1H, J = 5.4 Hz), six.06 (s, 1H), 7.03 (m, 2H), 7.33 (d, 1H, J = 8.Mal-PEG2-NHS ester site 1 Hz).tert-Butyl oct-7-yn-1-ylcarbamate supplier 13C NMR (CDCl3, 50 MHz) 18.PMID:23255394 2, 25.2, 25.4, 25.five, 28.two, 28.3, 28.six, 28.eight, 29.1, 31.7, 65.1, 67.0, 73.8, 110.9, 113.2, 116.five, 122.4, 124.two, 143.five, 151.9, 153.five, 160.1, 171.0. Rf (CHCl3/EtOAc 20:1) 0.67. []D20 -9.7?(c 0.99, CHCl3), known compound. (iv) (9a): To a answer of 7a (1.7502 g, five.26 mmol) in 25 mL of 1,4-dioxane was added a remedy of HCl (1.6 mL of 12 M aq. HCl diluted with 23.five mL 1,4-dioxane) at space temperature. The reaction was stopped just after 2 h. To this mixture was added 30 mL benzene and then freeze-dried to offer a white residue. The solid was re-dissolved in CHCl3 and purified on a silica gel column loaded with CHCl3 and eluted with CHCl3:EtOAc (two:1). The fractions corresponding towards the product were combined and evaporated, dissolved in benzene and freeze-dried to give 9a (1.3134 g, 91 ) as white solid. IR (CHCl3): 3340,.
