Synthesis of Chiral 12-Phenyl(2H)dodecanoic Acids: Useful metabolic probes for the biosynthesis of 1-alkenes from fatty acids

The synthesis of chiral 12-phenyi(²H)dodecanoic acids as metabolic probes for the evaluation of the stereo-chemical course of the biosynthesis of 1-alkerses from fatty acids in plants and insects is described. The diastereoisomeric (2R, 3R)- or (2S, 3S)-12-phenyl(2,3?²H₂)dodecanoic acids 11 are obtained in high chemical and optical yield (>97% e.e.) from the readily available (E)-12-phenyl(2,3-²H₂)dodec-2-enoic acid ( 10 ) or (E)-12-phenyldodec-2-enoic acid ( 10a ) by microbial reduction with wet packed cells of Clostridium tyrobutyricum in either ²H₂O or H₂O buffer. (2R)- and (2S)-12-phenyl(2?²H)dodecanoic acids 9 (>97% e.e.) are accessible from the allylic alcohol 6 via Sharpless epoxidation with (+)-L- or (?)-D-diethyl tartrate, Synthetic routes to the (E)- and (Z)-11-phenyl(1?²H) undec-1-enes 16 and 16a as reference compounds are also included.