Highly stereoselective allylic ethylation with alkoxytitanacyclopropane reagents. Synthesis of (1R/S,7R)-1,7-dimethylnonyl propanoate, the Western corn rootworm sex attractant
摘要:
Allylic ethylation of 2-((E)-dodec-2-en-4-yloxy)tetrahydro-2H-pyran with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide proceeds Via a S(N)2' pathway to afford (E)-3-methyltridec-4-ene with excellent syn-diastereoselecivity. This transformation is used as a key step in the synthesis of (1R/S,7R)- 1,7-dimethylnonyl propanoate, the Western corn rootworm (Diabrotica virgifera virgifera) sex attractant. (C) 2008 Published by Elsevier Ltd.