反应详情

A(ii)(a) A solution of 18 g of 2(R)-hydroxy-4-phenylbutanoic acid in 200 ml of dichloromethane containing 20.5 g of triethylamine and 250 mg of 4-(dimethylamino)pyridine was stirred at room temperature and treated dropwise with 12 g of acetic anhydride. The resulting mixture was stirred for a further 3 hours and then acidified by the addition of 125 ml of 2N sulphuric acid. The organic phase was separated and washed with two 100 ml portions of 2N sulphuric acid, then with 100 ml of water and finally with 100 ml of saturated sodium chloride solution, dried over anhydrous magnesium sulphate and evaporated in vacuo to give 22 g of 2(R)-acetoxy-4-phenylbutanoic acid as a colouless viscous oil; [α]43620 =+13.7° (c=1 in ethanol).

1. customThe organic phase was separated
2. washwashed with two 100 ml portions of 2N sulphuric acid
3. dry with materialwith 100 ml of water and finally with 100 ml of saturated sodium chloride solution, dried over anhydrous magnesium sulphate
4. customevaporated in vacuo