Stereoselective Synthesis of Both Enantiomers of Trifluoro-gamma-Valerolactone and Pentafluoro-gamma-Caprolactone

Both enantiomers of 5-(trifluoromethyl)dihydrofuran-2-one (1a) and 5-(pentafluoroethyl)dihydrofuran-2-one (1b) have been synthesised stereoselectively, in four steps, starting from chiral (R)- or (S)-3-[(4-methylphenyl)sulfinyl]propionic acid (2) and commercially available perfluorinated esters. Compound (+)-(S)-1b is the pentafluoro analogue of the aggregation pheromone of Trogoderma glabrum.