Acetone → Hydroxymethyl coumarin

Participants

Reaction Conditions

Reaction Steps

In a 25-mm-diameter test tube with a side tubulation for applying vacuum was placed 7-hydroxymethylcoumarin (300 mg, 1.70 mmol) and 2-deoxy-3,5-di-O-p-toluoyl-α-D-ribofuranosyl chloride (600 mg, 1.54 mmol). The test tube was tightly stoppered, and about 1 mm vacuum was applied to the tube through the tubulation. The evacuated tube was then heated in an oil bath at 110° C. for 5 min. During the first 2 min of heating there was vigorous evolution of HCl gas. The reaction mixture was then cooled to room temperature, and the residue was taken up in 3 to 4 ml of a 1:1 mixture of acetone and hexane. The solution was then submitted to chromatography on a 50 mm ×150 mm silica gel column using acetone/hexane 1:1 as the eluant. The fractions containing product were identified by TLC and were pooled and concentrated to a glass. The glass was taken up in 10 ml of ethyl acetate. The ethyl acetate solution in a 50 ml Erlenmeyer flask was placed in a jar containing 20 ml of pentane. The jar was then sealed and the crystallization was allowed to proceed. Yield was 330 mg of white crystals (41% of theory); the melting point was 92°-106° C. Rf =0.48 in acetone/hexane 1:1. NMR showed this material to be approximately a 1:1 mixture of α and β -anomers.

Provenance & Evidence