(E)-6-[tert-butyl(dimethyl)silyl]oxyhex-2-enoic acid

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A mixture of (E)-6-(tert-butyldimethylsilyloxy)hex-2-enoic acid (12.0 g, 49.2 mmol), HATU (18.69 g, 49.2 mmol), DIEA (30 mL), tert-butyl 2-aminophenylcarbamate (2) (10.23 g, 49.2 mmol) in DCM was stirred at RT for 5 hours, The reaction mixture was poured onto 500 mL of ethyl acetate and 200 mL of water, the organic layer was washed with water (250 mL×3) and brine (3×200 mL), dried over Na2SO4 and concentrated to give the desired compound of (E)-tert-butyl2-(6-(tert-butyldimethylsilyloxy)hex-3-enamido)phenylcarbamate (13.1 g, 44%) as a yellow oil after purification by column chromatography on silica gel (eluent: PE:EA=8:1). LC-MC (M+1) 435 (M+H)+ the organic layer was washed with water (250 mL×3) and brine (3×200 mL) dried over Na2SO4 concentrated

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of (E)-ethyl 6-(tert-butyldimethylsilyloxy)hex-2-enoate (7) (27.2 g, 0.1 mol) in THF and MeOH was added LiOH (6.6 g, 0.3 mol) in 50 mL H2O, the mixture was stirred at RT for 5 hours. After removal of the solvent, the residue was poured into 3N HCl to the pH value was adjusted to 4-5, then extracted with DCM (250 mL×2), and the organic layers were washed with water (250 mL×3) and brine (3×200 mL), dried over Na2SO4 and concentrated to give the desired compound of (E)-6-(tert-butyldimethylsilyloxy)hex-2-enoic acid (8) (12.1 g, 50%) as a yellow oil after purification by column chromatography on silica gel (eluent: PE:EA=5:1). 1H NMR (300 MHz, CDCl3): δ 0.0021 (S, 6H), 0.0857 (S, 9H), 1.600 (m, 2H), 1.197 (t, 3H), 2.240 (q, 2H), 3.586 (t, 2H), 5.832 (d, J=15.6 Hz, 1H), 6.936-6.885 (m, 1H); LC-MS found 245 (M+H)+. After removal of the solvent the residue was poured into 3N HCl to the pH value extracted with DCM (250 mL×2) the organic layers were washed with water (250 mL×3) and brine (3×200 mL) dried over Na2SO4 concentrated