Methanol → HCID 58609538, compound

Participants

Reaction Steps

6.0 g (27.39 mmol) of 3,4-dichloro-1,5-dimethyl-8-oxa-bicyclo[3.2.1]octa-3,6-dien-2-one is introduced into 39 ml of anhydrous methanol. At a temperature of 0° C., the reaction mixture is further diluted dropwise with a solution of 15.2 ml of 5.4M sodium methanolate (82.17 mmol) and treated with 10 ml of absolute methanol. The reaction mixture is then heated to ambient temperature with 35 minutes' stirring. Using thin-layer chromatography (hexane/ethyl acetate 8:2) it can be established that reaction of the starting material is complete. The reaction solution is then concentrated under reduced pressure. The residue is then extracted by means of carbon tetrachloride against water. The aqueous phase is extracted a further three times using fresh carbon tetrachloride. The combined organic extracts are dried over sodium sulfate and concentrated by evaporation under reduced pressure; with ice-cooling, the oily product that remains behind crystallises out in the form of a ˜1:1 mixture. The mixture is separated by means of column chromatography on silica gel (eluant: gradient from 1-5% ethyl acetate/hexane). 3.1 g (52.9%) of pure 3-chloro-1,5-dimethyl-4-methoxy-8-oxa-bicyclo[3.2.1]octa-3,6-dien-2-one are isolated.

Provenance & Evidence