Acetic Acid → Ethyl 9-oxo-3-thiabicyclo[3.3.1]nonane-7-carboxylate

Participants

Reaction Steps

A mixture of triethylamine (10.1 ml, 72 mmol) and 3,6-dihydro-4-(1-pyrrolidinyl)-2H-thiopyran (12.9 g, 76 mmol, prepared according to a procedure described in Tetrahedron Asymmetry 1997, 1811-1820) in anhydrous acetonitrile (55 ml) was heated to reflux, then ethyl 3-bromo-2-(bromomethyl)propionate (14.6 g, 53 mmol) in dry acetonitrile (42 ml) was added dropwise over a period of 45 min. The resulting reaction mixture was refluxed for another 1.5 hours, then cooled to room temperature before a 10% aqueous acetic acid solution (5.2 ml) was added. The mixture was then refluxed for 1 hour and evaporated to dryness. Brine was added to the residue, the aqueous phase was extracted with ethyl acetate, the combined organic extracts were dried over anhydrous sodium sulphate, filtered and concentrated in vacuo to yield 9-oxo-3-thia-bicyclo[3.3.1]nonane-7-carboxylic acid ethyl ester as a brown oil (15.5 g).

Provenance & Evidence