Pyridine → HCID 13188191, compound

Participants

Reaction Conditions

Reaction Steps

A solution of pyridine (6.8 g, 0.086 mol) and chromium trioxide (4.3 g, 0.043 mol) in methylene chloride (450 ml) at 23° C. in a nitrogen atmosphere is stirred for 45 minutes. The mixture is cooled to -20° C. and celite (20 g) is added followed by 6,6-ethylenedioxy-2-methyl-2-(4'-methyl-5'-hydroxypentyl)-oxepane (1.95 g, 0.00717 mol) in methylene chloride (50 ml). The mixture is stirred for 1 hour at -20° C. and 30 minutes at 0° C. The mixture is then filtered and the celite cake is washed with methylene chloride (10×50 ml). The filtrate and washings are combined and washed with satd. NaHCO3 (2×150 ml). The methylene chloride phase is separated, dried (MgSO4) and the solvents are removed at reduced pressure. The crude product (1.9 g) is chromatographed on SilicAR CC-7 (50 g) in hexane. Elution with 15% ethyl acetate/hexane gives 6,6-ethylenedioxy-2-methyl-2-(4'-methyl-5'-oxopentyl)-oxepane (19) as a clear colorless oil (1.33 g, 68%): nmr (CDCl3) δ1.10 (d, J=6 Hz, 3H, CH3 --CH--CHO), 3.42 (s, 2H, O--CH2 --C), 3.97 (s, 4H, ketal), 9.53 (d, J=2H, 1H, CH--CHO).

Provenance & Evidence