[OH:1][CH2:2][CH2:3][CH2:4][CH2:5][CH:6]1[CH2:13][CH2:12][O:11][C:9](=[O:10])[CH2:8][CH2:7]1.N1C=CN=C1.[Si:19](Cl)([C:22]([CH3:25])([CH3:24])[CH3:23])([CH3:21])[CH3:20].O>CN(C)C=O>[Si:19]([O:1][CH2:2][CH2:3][CH2:4][CH2:5][CH:6]1[CH2:13][CH2:12][O:11][C:9](=[O:10])[CH2:8][CH2:7]1)([C:22]([CH3:25])([CH3:24])[CH3:23])([CH3:21])[CH3:20]To a solution of 8.77 g (47 mmol) of 4-(4-hydroxybutyl)-epsilon-caprolactone (example 28) in 52 ml dry dimethylformamide is added 6.16 g (90 mmol) of imidazole followed by 11.1 g (71 mmol) of t-butyldimethylsilyl chloride (97% pure) and then the mixture is stirred for 16 h. The reaction mixture is poured into water and extracted twice with ether. The combined organic extracts are washed twice with water, brine, dried, filtered and concentrated to give an oil which is purified by flash chromatography using 3:2 hexane/ether to yield 4-(4-t-butyldimethylsilyloxybutyl)-epsilon-caprolactone as an oil; NMR (CDCl3): delta 4-4.3 (m,2H), 3.6 (t,2H), 0.88 (s,9H).
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