The stereospecific synthesis of chiral methyl trans-and cis-chryaanthematee (1 and 26) from (+)-and (-)-camones (7a, b) is described. Methyl (3R)-and (3S)-3-(l-chloro-l-methylethyl)-5- oxohexanoates (3) and methyl (3s)-and (3R)-3-(l-chloro-l-methylethyl)-5, 5- dimethoxypentanoates (4) are key intermediates in the preparation of 1 and 26 via I-ladone 2. Electrochemical cleavage of 5-(l-chlor~ l-methylethyl)-2, 3-epoxy-2, 3-d~ e~ yl~ clohe~-l ...