9-Phospha-bicylco [6.1.0] nona-2,4,6-triene 9-Phospha-bicylco [4.2.1.] nona-2,4,7-triene

The synthesis of the title compounds with substituents R=Alkyl, Cl, H by reaction of COT^2? with RPCl₂ at ?70°C is described.     

Thionin oxide as a Possible Intermediate on Periodate Oxidation of 9-Thiabicyclo[6.1.0]nona-2,4,6-triene

9-Thiabicyclo[6.1.0]nona-2,4,6-triene was oxidized at ?15 to ?20°C with sodium periodate in a methanol-water medium. The major isolated product was established as $\text{cis}$3a,7a-dihydrobenzo[b]thiophene-$\text{cis}$-1-oxide, which is best explained as arising from intramolecular cycloaddition of a thionin oxide intermediate.     

On the mechanism of the reductive cleavage of anti-9-phenyl-cis-bicyclo[6.1.0]nona-2,4,6-triene

Treatment of the title compound (1a) with potassium in liquid ammonia at ca ?33° immediately afforded the benzylcyclooctatetraene dianion (4a) which, upon quenching with iodine-pentane, gave benzylcyclooctatetraene (5) as the only isolable product. In contrast, treatment of1a with potassium amide in liquid ammonia at ?69° initially afforded the 9-phenylmethylenecyclooctatrienyl anion (6a) as a short-lived intermediate which was then converted to the α-aminobenzylcyclooctatetraene dianion (7a). These results, coupled with the observation that cis-bicyclo[6.1.0]nona-2,4-diene (12) in potassium amide-liquid ammonia affords the cis-bicyclo[6.1.0]nonadienyl anion (8b) which then slowly opens to the methylcyclooctatetraene dianion (4b) at ?12°, lead to the conclusion that4a is produced by a reductive cleavage of1avia a radical anion or dianion.     

The reaction of diiron nonacarbonyl with cis-bicyclo[6.2.0]deca-2,4,6-triene

The reaction of diiron nonacarbonyl with cis-bicyclo[6.2.0]deca-2,4,6-triene in ether at room temperature produces several products which are separable by chromatography on alumina. Compound (A), C₁₀H₁₂Fe₂(CO)₆, obtained in 23% yield, is shown by PMR and IR spectra to have the FeFe bonded Fe₂(CO)₆ group attached to the triene portion of the starting bicyclotriene. Compound (B), C₁₀H₁₂Fe(CO)₃, obtained both from the initial reaction and by heating (A) in refluxing toluene; is the Fe(CO)₃ adduct of tricyclo[4.4.0.0^2.5]deca-7,9-diene, a molecule which has not been isolated in the free state. Compound (C), also obtained on pyrolysis of (A) in minute yield, has not yet been characterized. Compound (D), C₁₀H₁₂Fe₂(CO)₆, from the original reaction, in small yield, appears to have separate Fe(CO)₃ groups bonded to the olefinic portions of a C₁₀H₁₂ monocycle, but spectral data alone do not allow a complete specification of the structure.     

The Synthesis and Chemistry of 9-Chlorobicyclo[6.1.0]Non-1(9)-Ene

9-Chlorobicyclo[6.1.0]non-l(9)-ene ( 4 ), a 2-chlorinated 1,3-fused cyclopropene, is synthesized and isolated from the dehalogenation of the l-bromo-9,9-dichlorobicyclo[6.1.0]nonane, itself derived from cyclooctene. Compound 4 undergoes ring opening reaction to generate cyclooctenyl chlorocarbene ( 9 ) which reacts with water via conjugate addition and ipso-addition to give ( E )-2-(chloromethylene)cyclooctanol ( 7 ) and cyclooctene-l-carboxaldehyde ( 8 ), respectively. The conjugate addition of 9 with water is more favorable than the ipso-addition by 3:1. Compound 4 , which is stable at ?25 °C for weeks without any decomposition, reacts with oxygen to produce 2-chlorocyclonon-2-enone ( 12 ) via the ring-opening reaction adduct, vinyl alkylcarbene 10 .