2,2-Dimethyl-1,3-dioxane-4,6-dione → tert-Butyl (3-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)-3-hydroxypropyl)carbamate

Participants

Reaction Steps

A stirred solution of 2,2-dimethyl-[1,3]dioxane-4,6-dione (7.5 g, 52 mmol), 3-tert-butoxycarbonylamino-propionic acid (9.45 g, 50 mmol), 4-dimethylamino pyridine (9.6 g) in dichloromethane (525 ml) was added dropwise slowly with the solution of N-ethyl-N′-(dimethylaminopropyl)-carbodiimide hydrochloride (11 g, 57.5 mmol) in 352 ml of dichloromethane in an ice-water bath. Upon completion of the addition, the mixture was stirred at room temperature overnight, then washed with 5% aqueous potassium bisulfate solution (300 ml×4), dried with anhydrous sodium sulfate, filtered and concentrated to give [3-(2,2-dimethyl-4,6-dioxo-[1,3]dioxin-5-ylidene)-3-hydroxy-propyl]-carbamic acid tert-butyl ester which was used as such.

Provenance & Evidence