Potassium Carbonate → Di-tert-butyl (4S)-N-(tert-butoxvcarbonyl)-4-[4-({2-phenyl-5-[(tosyloxy)methyl]-1,3-dioxan-5-yl}methoxy)benzyl]-L-glutamate

Participants

Reaction Conditions

Reaction Steps

To 466 mg (1.0 mmol) of di-tert-butyl (4S)—N-(tert-butoxycarbonyl)-4-(4-hydroxybenzyl)-L-glutamate in 12 mL N,N-dimethylformamide were added 138 mg (1.0 mmol) of potassium carbonate and 533 mg (1.0 mmol) of (2-phenyl-1,3-dioxane-5,5-diyl)bis(methylene) bis(4-methylbenzenesulfonate) (Heterocycles 34. (1992), 739), and the resulting suspension was heated for 2 h at 100° C. in a microwave oven. The reaction mixture was then filtered, the solvent evaporated and the residue was taken up in ethyl acetate and water. The organic phase was separated off, washed with water until neutral, dried over sodium sulfate and filtered, and the filtrate was concentrated in vacuo. The residue was chromatographed on silica gel using a dichloromethane/ethyl acetate gradient, and the appropriate fractions were combined and concentrated.

Provenance & Evidence