Search

The regioselective two-step sequence of bromination-dehydrobromination of 2-(2,2-diethoxy)-1-methyl-1-cyclopropanol affords 3-(2,2-diethoxyethyl)-3-buten-2-one in high yield. The reduction of the latter, followed by chlorination and dehydrochlorination, provides 2-(2,2-diethoxyethyl)-1,3-butadiene that was used as a building block for the synthesis of (±)-ipsenol, (±)-ipsdienol and amitinol - the components of aggregation pheromones of the Ips bark beetles.

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 SN2′ 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.

A convenient new approach to the synthesis of the C13–C21 epothilone fragment using the cyclopropanation of the ethoxycarbonyl groups in O-THP protected diethyl (S)-malate with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide followed by site-selective cyclopropane cleavage as the key steps has been performed.