反应详情

Imidazole (125 mg, 1.84 mmol, 2.2 equiv) and tert-butyl-dimethylsilyl chloride (139 mg, 0.92 mmol, 1.1 equiv) are added to a solution of (3S)-3-(tert-butyldimethylsilyloxy)-2-hydroxy-2-methyl-tetrahydrofurane 13 (194 mg, 0.83 mmol) in dimethyl formamide (800 μl). The mixture is stirred for 24 h at r.t. Purification of the reaction mixture by flash column chromatography (pentane/diethyl ether 20:1) affords (S)-3,5-di-(tert-butyidimethylsilyloxy)pentan-2-one 14 (226 mg, 78%) as a colourless oil. [α]D20=−11.8; [α]54620=−14.1 (c=1.0, CHCl3); 1H-NMR (200 MHz, CDCl3): δ(ppm)=4.16 (dd, 1H); 3.8-3.5 (m, 2H); 2.16 (s, 3H); 1.9-1.7 (m, 2H); 0.92 (s, 9H); 0.88 (s, 2H); 0.06 (s, 6H); 0.04 (s, 3H), 0.03 (s, 3H)

1. customPurification of the reaction mixture by flash column chromatography (pentane/diethyl ether 20:1)