Reaction Steps
Sodium hydride dispersion (0.377 g, 12.6 mmol, 80% in oil) was washed with dry ether under nitrogen. The residue was resuspended in dry DMF (30 ml), and 6,6-dimethoxyhexan-1-ol (1.62 g, 10 mmol) was added. The mixture was heated at 80° C. for 1.25 hr., during which time the sodium hydride reacted. (R)-1-(Benzyloxy)-2,3-epoxypropane (1.64 g, 10 mmol) was added and heating was continued for 2 hr. Upon cooling, water (100 ml) was added and the mixture was extracted with ether (100 ml, 2×40 ml). The combined extracts were washed with water (2×80 ml) and brine (10 0 ml), dried (MgSO4) and evaporated. The residual oil (2.8 g) was dissolved in chloroform (36 ml), and cooled to 0° C. Pyridine (3.5 ml, 43 mmol) and freshly distilled acetyl chloride (0.94 ml, 13.2 mol) were added. The mixture was stirred for 0.5 hr. at 25° C., then 2 hr. at room temperature (RT). Ice water (100 ml) was added and the layers separated. The aqueous layer was extracted with chloroform (2×40 ml), and the combined organic phases were washed with water (100 ml) and brine (100 ml), dried (MgSO4) and evaporated. The residue was subjected to chromatography and the product was eluted with petroleum ether-ethyl acetate (9:1). Evaporation of this fraction yielded the product as a colorless oil (1.82 g, 50%) b.p. 170° C./0.2 mmHg (C20H32O6 requires C, 65.19; H, 8.75%, Found: C, 65.06%; H,8.66%), [α]D +1.98° (c 5.06, benzene). 1H N.M.R.δ:7.36, m,5, ArH; 5.17,q.l,J 5.0 Hz, H2; 4.50,d,2,J 2.5 Hz, benzyl; 4.36, t,l,J 5.7 Hz, --CH(OMe2); 3.62d,2,J 5.0 Hz, H3; 3.58,d,2,J 5.2 Hz, OCH2 --; 3.48-3.39, m,2,H1; 3.31,s,6,OCH3; 2.12,s,3,COCH3; 1.72-1.26,m,8,--CH2 --. Mass spectrum: m/e 337, 305, 287, 245, 229, 215, 207, 146, 117, 113, 111, 91, 81, 75, 72.
