(4S,5S)-5-azidomethyl-4-methyl-4,5-dihydro-2(3H)-furanone

methyl (3R,4R)-(-)-4,5-epoxy-3-methylpentanoate

(4R,5S)-dihydro-5-hydroxymethyl-4-methyl-2(3H)-furanone

cis-4-methyl-2-oxo-5-(2,2,2-trichloroethyl)tetrahydrofuran

cis-5-(2,2-dichloroethyl)-4-methyl-2-oxotetrahydrofuran