p-Toluenesulfonate → 2-Oxaspiro[4.5]dec-7-ene

Participants

Reaction Conditions

Reaction Steps

Diazabicyclononene (DBN) (76.2 g., 0.61 mole) was stirred and heated at 90° C. while the tosylate from Part E above (133.2 g. (0.43 mole)) was added portionwise. When the addition was completed the mixture was stirred at 110° C. for one hour then cooled in an ice-water bath. The mixture was then diluted with hexane causing the precipitation of salts. The resulting suspension was filtered and the solid filtered salts were washed with hexane. The hexane solution was concentrated on a rotating evaporator to a residue of 210 g. of a pale yellow liquid. This liquid was distilled to give 84.6 g. (74% yield) of the 2-oxaspiro[4.5]dec-7-ene as a relatively pure material which was not further purified.

Provenance & Evidence