2,2-Dimethoxypropane → HCID 20077579, compound

Participants

Reaction Steps

p-Toluenesulphonic acid monohydrate (13.4 g) was added to a solution of compound B (20.0 g) in 2,2-dimethoxypropane (100 ml) and the mixture was stirred for 18 hours at ambient temperature. A 1M solution of tetrabutylammonium fluoride in THF (150 ml) was then added and the mixture stirred for a further 15 minutes. The reaction mixture was then neutralised with excess saturated aqueous sodium bicarbonate solution and extracted three times with ethyl acetate. The combined extracts were dried (MgSO4) and concentrated and the residue was purified by column chromatography, eluting with 25% ethyl acetate/hexane (v/v), to give (4RS,5RS)-5-allyl-2,2-dimethyl-4-(5-thiazolyl)-1,3-dioxane (C) (13.0 g; 85% yield) as an oil; NMR: 1.45-1.55(6H,m), 1.6-2.05 and 2.4-2.5(3H,m), 3.68-4.16(2H,m), 4.9-5.1 and 5.5-5.72(4H,m), 7.72 and 7.81(isomers,1H,2s), 8.72 and 8.79(isomers, 1 H,2s).

Provenance & Evidence