Synthesis of optically active cyphenothrin-14C

Optically active cyphenothrins, α-cyano-3-phenoxybenzyl (1R)-cis- and (1R)-trans-chrysanthemates, were labelled with 14C independently at the cyano and the benzyl carbons for use in metabolic studies. α-Cyano-14C-3-phenoxybenzyl alcohol (4) prepared from potassium cyanide-14C (2) was condensed with (1R)-cis- or (1R)-trans-chrysanthemoyl chloride (5a or 5b) to give (1R)-cis- or (1R)-trans-cyphenothrin-(cyano-14C) (1a or 1b) in the yield of 82 or 95 % from 2, respectively. Similarly, α-cyano-3-phenoxybenzyl-α-14C alcohol (12), which was synthesized from barium carbonate-14C (6) in four steps, was esterified with 5a or 5b to afford (1R)-cis- or (1R)-trans-cyphenothrin-(benzyl-14C) (1c or 1d). The overall yields of 1c and 1d were 61 and 69 % from 6, respectively. (author)