Bicyclo[2.2.1]heptane-1-methanesulfonic acid, 7,7-dimethyl-2-oxo-, (1S)- → 8-[2,4-Bis(methoxymethoxy)phenyl]-1,4-dioxaspiro[4.5]dec-7-ene

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Reaction Steps

8-[2,4-Bis(methoxymethoxy)phenyl]-1,4-dioxaspiro[4.5]decan-8-ol (1.40 g) was placed in a round bottomed flask fitted with Dean-Stark apparatus. Toluene (30 ml) was added, followed by camphor sulphonic acid (10 mg). The stirred solution was then heated under reflux for 1 hr, cooled, and saturated aqueous sodium bicarbonate solution (10 ml) added. The mixture was poured into a separating funnel and the phases separated. The aqueous phase was extracted with ethyl acetate (2×15 ml) and the combined organics were washed with brine (15 ml), dried over anhydrous magnesium sulphate, filtered and then concentrated in vacuo yielding an orange oil, which was purified by flash column chromatography (SiO2, ethyl acetate/petroleum ether, 45:55, v/v) to afford the title product (0.94 g) as a colourless oil. δH (CDCl3) 1.84 (2H, t), 2.41-2.43 (2H, m), 2.56-2.62 (2H, m), 3.47 (6H, s), 3.98-4.02 (4H, m), 5.13 (4H, s), 5.58-5.63 (1H, m), 6.64 (1H, dd), 6.78 (1H, d), 7.08 (1H, d).

Provenance & Evidence