3,4-dimethylpent-4-en-2-one

ethyl 4,5-dimethyl-2-methylidenehex-5-enoate

ethyl (E)-5-methyl-2-methylenehept-5-enoate

(2R,4S)-2-Bromomethyl-4,5-dimethyl-hex-5-enoic acid ethyl ester

ethyl (2R,4R)-2-(bromomethyl)-4,5-dimethylhex-5-enoate