Abstract
A convenient method is described for the stereoselective synthesis of methyl trans - 3 - (2, 2 -dichloroethenyl) - 2, 2 - dimethylcyclopropanecarboxylate (5) via methyl 3, 3 - dimethyl - 4, 6, 6, 6 -tetrachlorohexanoate (4) as a key intermediate, which was obtained by addition of carbon tetrachloride to methyl 3,3-dimethyl-4-pentenoate (3). Treatment of (4) with sodium methoxide in a single-vessel via methyl 4,6,6-trichloro-3.3-climethyl-5-hexenoate (6) gave trans-rich (5) in excellent yield.