6,6-Ethylenedioxy-2-methyl-2-(4'-oxobutyl)-oxepane → 6,6-Ethylenedioxy-2-(4'-hydroxypentyl)-2-methyloxepane
Reaction equation
[CH3:1][Li].[CH2:3]1[CH2:19][O:18][C:5]2([CH2:11][O:10][C:9]([CH3:17])([CH2:12][CH2:13][CH2:14][CH:15]=[O:16])[CH2:8][CH2:7][CH2:6]2)[O:4]1>CCOCC>[CH2:19]1[CH2:3][O:4][C:5]2([CH2:11][O:10][C:9]([CH2:12][CH2:13][CH2:14][CH:15]([OH:16])[CH3:1])([CH3:17])[CH2:8][CH2:7][CH2:6]2)[O:18]1Participants
4
Procedure
Methyllithium (10 ml, 0.0184 mol, 1.84 M in hexane) is added dropwise to a solution of 6,6-ethylenedioxy-2-methyl-2-(4'-oxobutyl)-oxepane (3.3 g) in ether (150 ml) at 0° C. in a nitrogen atmosphere. The cooling bath is removed and the mixture is stirred for 0.5 hour at ambient temperature. The mixture is poured into cold satd. NaCl (300 ml). The ether layer is separated and the aqueous layer extracted with ether (3×50 ml). The ether phases are combined, dried (MgSO4) and the solvent is removed at reduced pressure. The crude product (3.6 g) is chromatographed on SilicAR CC-7 (70 g) in hexane. Elution with 15% ethyl acetate/hexane gives 6,6-ethylenedioxy-2-(4'-hydroxypentyl)-2-methyloxepane (15) as a clear colorless oil (3.3 g, 94%).