X-Ray analysis of synthetic (4S)-2-(prop-2-enyl)rethron-4-yl (1R,3R)-chrysanthemate 6-bromo-2,4-dinitrophenylhydrazone, and chiroptical correlation with the six natural pyrethrin esters

Abstract

The X-ray structure and absolute configuration of (4S)-2-(prop-2-enyl)rethron-4yl (1R,3R)-chrysanthemate (10) have been determined for the 6-bromo-2,4-dinitrophenylhydrazone derivative, a= 9·840 ± 0·008, b= 7·724 ± 0·01, c= 19·783 ± 0·015 Å, β= 105·00 ± 0·05°, Z= 2, space group P2₁ for 614 observed reflections. Chiroptical data (o.r.d. and c.d.) for (10), and for the six natural pyrethrin esters (1)–(6), show that the latter all have the same S-configuration at C(4).