Maltol → 3-(3-Hydroxypropoxy)-2-methyl-4H-pyran-4-one

Participants

Reaction Steps

A suspension of 3-hydroxy-2-methyl-4-pyrone (25 g, 200 mmol), 3-bromo-1-propanol (70 g, 500 mmol) and K2CO3 (111 g 800 mmol) in 600 ml acetone was stirred for three days. The solvent was evaporated and the residue partitioned between 300 ml methylene chloride and 500 ml 2.5% NaOH. The aqueous layer was separated and extracted with 2×300 ml methylene chloride. The organic phases were combined, dried over Na2SO4 and evaporated at 50° C. Eight grams of the residue (24 g) was chromatographed on silica gel with methanol/methylene chloride (5:95) as eluent which afforded 2.7 g (22%) of the desired product as an oil.

Provenance & Evidence