2-Hexanone → HCID 14174973, compound

Participants

Reaction Conditions

Reaction Steps

A vigorously stirred solution of (4aR,7R,8aR)-hexahydro-4,4,7-trimethyl-4H-1,3-benzoxathiin (9 g, 0.045 mole, prepared as described by ELIEL et al. Org. Synth. 65, 215 [1987]) in 130 ml of anhydrous tetrahydrofuran was cooled to -78° C. under an ar8on atmosphere and butyllithium (3.168 g, 0.0195 mole) dissolved in 32 ml of hexane was added dropwise over a period of 15 minutes. The solution was further stirred for additional 15 minutes. The temperature of the solution was allowed to slowly reach 0° C. and further stirred for 15 minutes. The solution was cooled again to -78° C. under the argon atmosphere, the stirring was continued and 2-hexanone (4.5 g, 0.045 mole) dissolved in 25 ml of anhydrous tetrahydrofuran was added dropwise over a period of 20 minutes. The solution was further stirred for additional 4 hours. The temperature of the solution was allowed to slowly reach the room temperature, 10 ml of water were added dropwise over a period of 10 minutes and then 15 ml of a saturated solution of ammonium chloride in water were added at once. The reaction mixture was S partitioned between diethyl ether and water. The ether portion was washed with brine, dried over anhydrous Na2SO4 which was then removed by filtration, and evaporated to leave 13.1 g of a thick syrup. This thick syrup was dissolved in 10 ml of hexane-ethyl acetate (9:1 v:v) solvent and chromatographed on 1000 g of silica gel (230-400 mesh ASTM). The 5 liters of hexane-ethyl acetate that were eluted, were evaporated in vacuo to leave a viscous colorless liquid residue. This liquid was distilled at reduced pressure. The fraction distilling at 95°-97° C. and 0.05 Torr was collected yielding 6.2 g (45.9%) of the title compound, which shows [α]365 =-28.91° (C=1.61 in CHCl3). Anal. Calcd. for C17H32O2S: C,67.96; H,10.74; O,10.65; S,10.65, Found: C,68.20; H,10.63; O,10.47; S,10.56.

Provenance & Evidence