Cyclodiene Chemistry. IV. Assignment of Configuration of Two Nonachlors via Synthesis and Derivatization

Abstract

The configuration of nonachlor, mp 128- 130°C, was elucidated, from both the structure of its dehydrochlorinated product and the synthesis of stereoisomeric nonachlor, as possessing a l-exo,2-endo,3-exo (i.e., trans-nonachlor) chlorine arrangement in the cyclopentane ring. Dehydrochlorination of transnonachlor yields 1,2-dichlorochlordene, the structure of which was established by specific allylic dechlorination to 2-chlorochlordene. Further confirmation was obtained by conversion to l-keto-2-chlorochlordene. An alternative synthesis of this chloroketone from 1-ketochlordene is described. An isomeric nonachlor, mp 214-215°C, with the l-exo,2-exo, 3-exo (i.e., cis-nonachlor) chlorine arrangement was prepared from a heptachlor chlorohydrin of known configuration. Dehydrochlorination of cis-nonachlor gave 1,3-dichlorochlordene. The reactions of these 2 nonachlors with base is discussed with reference to cisand trans-chlordane.

Enantioselective determination of chlordane components using chiral high-resolution gas chromatography-mass spectrometry with application to environmental samples

“…'Peak number and retention index (DB-5); see ref 2. more complex structures present in the technical mixture, resulting from rearrangement reactions (e.g., Wagner-Meerwein rearrangement), and we refer the reader to the studies by Dearth and Hites (2) and others for more detailed information. The structures of several compounds were elucidated byand 13C-NMR spectroscopy and X-ray crystallography (2,11,12,25,(28)(29)(30).…”

Chlordane photoalteration products. Preparation and identification

“…(The transnonachlor used in this study had the same melting point and glc properties as reported by Biichel in 1966; he proposed that the three chlorines on the cyclopentane ring were probably all cis to each other and exo to the CC12 bridge.) The synthesis of the all-cw-nonachlor (IX) has been reported (Cochrane et al, 1970). This nonachlor isomer has a much higher melting point than Pww-nonachlor, and apparently photolyzes to the half-cage compound (X) (Cochrane, 1969).…”

Synthesis and mass spectra of 37Cl6-hexachlorocylopentadiene and derived organochlorine insecticides

“…Hexachlorocyclopentadiene-37CZ6 (0.75 g, 3.0 mmol) was reacted with cyclopentadiene (375 mL, 4.5 mmol) as previously reported (Heys et al, 1979) to give chlordene-4,5,6,7,8,8-37CZ6, which was subjected without purification to selenium dioxide oxidation (Kleinmann and Goldman, 1954). This crude 3-hydroxychlordene-4,5,6,7,8,8-37CZe was treated with thionyl chloride (Cochrane et al, 1970) to yield, after purification by column chromatography, 450 mg of heptachlor-4,5,6,7,8,8-37CZ6 (39% overall yield): mp [108][109][110] °C…”