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

The synthesis of chiral 12‐phenyi( 2 H)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 (2 R , 3 R )‐ or (2 S , 3 S )‐12‐phenyl(2,3− 2 H 2 )dodecanoic acids 11 are obtained in high chemical and optical yield (>97% e.e.) from the readily available ( E )‐12‐phenyl(2,3‐ 2 H 2 )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 2 H 2 O or H 2 O buffer. (2 R )‐ and (2 S )‐12‐phenyl(2− 2 H)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− 2 H) undec‐1‐enes 16 and 16a as reference compounds are also included.