2-Pyridinecarboxaldehyde → HCID 53872785, compound

Participants

Reaction Steps

(for Example 11): Potassium t-butoxide (8.40 g) was added under argon to a stirred, ice-cooled, mixture of 2-pyridinecarboxaldehyde (5.36 g) and (methoxymethyl)triphenylphosphonium chloride (25.65 g) in dry THF (100 ml). The mixture was stirred for 1 hour and was then poured into ice-water (100 ml). The mixture was extracted with ether (3×50 ml) and the organic solution extracted with 2M hydrochloric acid (3×25 ml). These acid extracts were washed with ether (25 ml), basified to pH 11 with 2M sodium hydroxide and extracted with ether (1×100 ml). These combined extracts were washed with water (25 ml), saturated brine (2×25 ml), dried (MgSO4) and evaporated. Flash chromatography, eluting with ether, gave 1-methoxy-2-(2-pyridyl)ethene as a yellow oil (4.03 g). A solution of this oil (810 mg) and methyl 4(Z)-6-(4-o-methylsulphonyloxyphenyl-2,2-dimethyl-1,3-dioxan-cis-5-yl)hexenoate (1.65 g) in acetonitrile (10 ml) was treated with p-toluenesulphonic acid monohydrate (1.25 g) and the mixture stirred at 80° C. for 18 hours. Ether (100 ml) was added to the cooled solution and the mixture washed with 5% w/v sodium bicarbonate (1×40 ml), saturated brine (2×25 ml), dried (MgSO4) and evaporated. Purification of the residue by MPLC, eluting with ethyl acetate/hexane (75:25) gave methyl 4(Z)-6-([2,4,5-cis]-4-o-methylsulphonyloxphenyl-2-[2-pyridylmethyl]-1,3-dioxan-5-yl)hexenoate as a pale yellow oil (1.50 g); NMR (CDCl3): 1.51 (1H, m), 1.88 (1H, m), 2.25 (4H, m), 2.41 (1H, m), 3.22 (3H, s), 3.29 (2H, d J=5 Hz), 3.68 (3H, s), 3.91 (1H, dm J=11 Hz), 4.06 (1H, bd J=11 Hz), 5.26 (4H, m), 7.15 (1H, m), 7.32 (4H, m), 7.60 (2H, m), 8.56 (1H, dd J=5, 0.5 Hz); m/e 476 (M+H)+.

Provenance & Evidence