ChemInform Abstract: POLYFLUORIERTE CYCLISCHE DIENE UND DIENONE 7. MITT. F‐19‐KERNRESONANZSPEKTREN VON POLYFLUORCYCLOHEXADIENONEN

Reactions of polyfluorinated cyclohexadienones with diazoalkanes. Part 1. Formation of cyclopropanes from polyfluorinated cyclohexa-2,4-dienones with diazomethane and phenyldiazomethane

“…The reaction of 6-chloro-2,3,4,5,6-pentafluorocyclohexa-2,4dienone (1) 9 with diazomethane in ether at 0 ЊC results in the formation of a 58 : 42 mixture of two isomers of 6-chloro-3a,4,5,6,7a-pentafluoro-3,3a,6,7a-tetrahydrospiro[indazole-7,2Ј-oxirane] (2a,b) in 52% overall yield (Scheme 2). The structure of compounds 2a and 2b was attributed on the basis of the analysis of 1 H and 19 F NMR spectra of a mixture of isomers (Table 1).…”

“…The reaction of 6-chloro-2,3,4,5,6-pentafluorocyclohexa-2,4dienone (1) 9 with phenyldiazomethane in acetonitrile (addition of the solution of diazoalkane to the solution of 1) also gave a mixture of the isomeric 6-chloro-3a,4,5,6,7a-pentafluoro-3,3Јdiphenyl-3,3a,6,7a-tetrahydrospiro[indazole-7,2Ј-oxirane] (3a and 3b, 67 : 33) but in low yield (5%). The main products of this reaction are the isomeric 3-chloro-1,3,4,5,6-pentafluoro-7- phenylbicyclo[4.1.0]hept-4-en-2-ones (4a and 4b, 62 : 38) (Scheme 3).…”

“…6-Chloropentafluorocyclohexa-2,4dienone (1) was prepared according to ref. 9. All other starting materials and reagents were obtained from Fluka or Acros.…”

N-halogeno-compounds. Part 7. Synthesis and iodine-catalysed rearrangement to 6-chloroimino-1-azacyclohexadienes of 4-substituted 2-(dichloroamino)-3,5,6-trifluoropyridines

“…the l-azacyclohexa-1,4-diene (11); also formed was the amide (12), the expected product of attack on the diene by adventitious moisture (Scheme 3). Iodine-catalysed isornerization of dichloroamines (7)-(9) (Y = Cl) gave mixtures of both possible 6-chloroimino-l-azacyclohexadienes (Scheme 2) ; these products also were extremely moisture-sensitive, addition of water to the diene mixture [predominantly (13)] derived from the 4H-compound (7; Y = C1) and to the major chloro-isomer (15) (isolated by g.1.c.)…”