Hexamethylphosphoramide → Benzyl 2-cyclopentyl-10-iododecanoate
Reaction equation
[CH:1]1([CH2:6][C:7]([O:9][CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)=[O:8])[CH2:5][CH2:4][CH2:3][CH2:2]1.[I:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25]I.CN(C)P(N(C)C)(N(C)C)=O>C1COCC1>[CH:1]1([CH:6]([CH2:25][CH2:24][CH2:23][CH2:22][CH2:21][CH2:20][CH2:19][CH2:18][I:17])[C:7]([O:9][CH2:10][C:11]2[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=2)=[O:8])[CH2:5][CH2:4][CH2:3][CH2:2]1Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
To a cooled (-78° C.) solution of lithium diisopropylamide (20 mmol) in a mixture of THF (20 mL) and hexane (8 mL) (obtained in situ from the corresponding diisopropylamine and n-BuLi) was added slowly the compound obtained in step 1(3.96 g, 18 mmol) in anhyd. THF(10 mL). The mixture was stirred for 30 minutes and 1,8-diiodooctane (7.19 g, 20 mmol) in hexamethylphosphoramide (3.50 g, 20 mmol), was added. The mixture was stirred at -78° C. for 30 minutes, slowly brought to 0° C. over a period of 2 h and quenched by the cautious addition of 50 mL of 12% aqueous sodium chloride solution. The mixture was extracted with ether, washed with brine, dried and the solvent was evaporated. The crude product was purified to an oil (3.23 g) by a flash chromatography over silica using hexane to 1% EtOAc in hexane as an eluant; 1H NMR (300 MHz, CDCl3) δ: 7.35(m, 5H), 5.15(s,2H), 3.20(t,8 Hz,2H), 2.20(m, 1H), 2.0(m, 1H), 1.2-1.8(m,22H)