17647-77-7Relevant articles and documents
FORMATION AND REARRANGEMENT OF TRICYCLO4,10>UNDECA-2,4,6,8,TETRAEN-10-OL, NOVEL PATHWAY FROM BICYCLOUNDECA-1(10),2,4,8-TETRAEN-11-ONE TO 4-METHYLAZULENE
Fujise, Yutaka,Morishima, Takashi,Namiwa, Kimiyoshi,Shiokawa, Toshihiro,Fukazawa, Yoshimasa,Ito, Sho
, p. 4261 - 4264 (1983)
Abstract: By the action of LDA bicycloundeca-1(10),2,4,8-tetraen-11-one was found to undergo transannular cyclization to form a unique tricyclic hydroxydihydroazulene which cleaves a C-C bond by electrocyclic process and eventually give 4-methylazulene.
Base-promoted Eliminations within Halogenated Propellene Frameworks
Banwell, Martin G.,Halton, Brian,Hambley, Trevor W.,Ireland, Neil K.,Papamihail, Con,et al.
, p. 715 - 724 (2007/10/02)
The reactions of halogenated propellenes with potassium t-butoxide have been investigated.Propelladiene 9,9-dichloro-1,4,5,8-tetrahydro-4a,8a-methanonaphthalene affords 1,6-methanoannulene, 4-methylazulene, and 5H-benzocycloheptene, while the related tetracyclic compound 1,1,8,8-tetrachloro-1a,2,3,6,7,7a-hexahydro-2a,6a-methano-1H-cyclopropanaphthalene reacts to give 12-chlorotricyclo3,5>dodeca-1,3(5),6,8,10-pentaene.Treatment of 8,8-dichloro-2,3,4,7-tetrahydro-3a,7a-methano-1H-indene with the same base produced a mixture of the chlorodiene 8-chloro-2,3-dihydro-3a,7a-methano-1H-indene, azulene, and 4-methylazulene.The structure of the chlorodiene was established by an X-ray crystallographic study of its Diels-Alder adduct with 4-phenyl-4H-1,2,4-triazole-3,5-dione.While reaction of tetracycle 1,1,syn-8-trichloro-1a,2,3,6,7,7a-hexahydro-2a,6a-methano-1H-cyclopropanaphthalene with base failed to produce any characterisable products, under the same conditions epimer 1,1,anti-8-trichloro-1a,2,3,6,7,7a-hexahydro-2a,6a-methano-1H-cyclopropanaphthalene was converted into the cycloproparene tricyclo3,5>dodeca-1,3(5),6,8,10-pentaene.Mechanistic proposals which account for the observed conversions have been advanced and are supported by 13C-labelling studies.The initial steps in most of the reaction pathways of the substrates are probably 1,4-elimination processes involving abstraction of an allylic hydrogen, fragmentation of the strained propellene ?-bond, and ejection of the halogen in an endo-relationship to the abstracted proton.The primary product of these processes, bridgehead dienes such as bicycloundeca-1,3,6(11),8-tetraene, 4,4,12-trichlorotricyclo3,5>dodeca-1(11), 7(12),9-triene and 10-chlorobicyclodeca-1,3,6(10)-triene, then undergo further reaction involving, amongst other things, 1,3-prototropic shifts.Attempts to probe the mode of formation of the C11-4-methylazulene from the C10-precursor 8,8-dichloro-2,3,4,7-tetrahydro-3a,7a-methano-1H-indene have uncovered a novel methylation reaction of azulene by the dimsyl anion.
