Photo-induced transformations. Part 76. Ring expansion through a [2 + 2] photocycloaddition-β-scission sequence; the photorearrangement of endo-4-cyanotricyclo[6.4.0.0]dodeca-1(12),6,8,10-tetraen-5-yl hypoiodite to 4-cyanotricyclo[6.4.0.0]dodeca-1 (12),6,8,10-tetraen-5-one. X-Ray crystal structure of 4-cyanotricyclo[6.4.0.0]dodeca-1(12),6,8,10-tetraen-5-one

1985 ◽  
pp. 327-329 ◽  
Author(s):  
Hiroshi Suginome ◽  
Chi Fu Liu ◽  
Masao Tokuda ◽  
Akio Furusaki
Keyword(s):  
Crystal Structure ◽  
Ring Expansion ◽  
X Ray

Tetrahydropyridine (THP) ring expansion under the action of activated terminal alkynes. The first synthesis and X-ray crystal structure of tetrahydropyrimido[4,5-d]azocines

2006 ◽  
Vol 47 (6) ◽  
pp. 999-1001 ◽  
Author(s):  
Leonid G. Voskressensky ◽  
Tatiana N. Borisova ◽  
Innokenti S. Kostenev ◽  
Larisa N. Kulikova ◽  
Alexey V. Varlamov
Keyword(s):  
Crystal Structure ◽  
Ring Expansion ◽  
Terminal Alkynes ◽  
X Ray

Unexpected Pyrolytic Behaviour of Substituted Benzo[c]thiopyran and Thieno[2,3-c]thiopyran S,S-dioxides

2014 ◽  
Vol 67 (9) ◽  
pp. 1288 ◽  
Author(s):  
R. Alan Aitken ◽  
Clémence Hauduc ◽  
M. Selim Hossain ◽  
Emily McHale ◽  
Adrian L. Schwan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ring Expansion ◽  
Hydrogen Atom Transfer ◽  
Membered Ring ◽  
X Ray ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Higher Temperature ◽  
Intramolecular Hydrogen ◽  
Carbonyl Products

Flash vacuum pyrolysis (FVP) of benzo[c]thiopyran S,S-dioxide (1) results in formation of indene and 2-vinylbenzaldehyde as previously described. A range of eight analogues with various substitution patterns are found to behave differently. In general, there is no extrusion of SO2 to give products analogous to indene, but unsaturated carbonyl products analogous to 2-vinylbenzaldehyde are formed in most cases by way of ring expansion to a 7-membered ring sultine, extrusion of SO, and intramolecular hydrogen atom transfer. Other processes observed include formation of anthracene via an isomeric 7-membered sultine with loss of SO, CO and methane or butane, and formation of 4-ethylidene-4,5-dihydrocyclobuta[b]thiophenes by way of SO loss, a radical rearrangement, and extrusion of acetone. The analogues with a halogen substituent at position 8 on the benzene ring require a higher temperature to react and give naphthalene resulting from net elimination of HX and SO2. The X-ray crystal structure of 1 is also reported.

Preparation of Thieno[3,2-e][1,2]oxazepine, Thieno and [1]Benzothieno-[3,2-g][1,4]oxazonine, and 5H-Thieno and 1H-[1]Benzothieno-[3,2-h][1,5]oxazecine Derivatives by Ring Expansion Methods. X-Ray Crystal Structure of 1-Phenyl-1,3,4,5,6,7-hexahydro[1]benzothieno-[3,2-g][1,4]oxazonine-5-carbonitrile

1988 ◽  
Vol 41 (12) ◽  
pp. 1815 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
LM Engelhardt ◽  
CS Greenwood ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Tertiary Amine ◽  
Cyanogen Bromide ◽  
Crystal And Molecular Structure ◽  
Ring Expansion ◽  
Standard Methods ◽  
X Ray ◽  
Medium Ring

10-Phenyl-4,5,6,7,8,10-hexahydrothieno[3,2-g][1,4]oxazonine-6-carbonitrile (6a) and 11-phenyl-4,6,7,8,9,11-hexahydro-5H-thieno[3,2-h][1,5]oxazecine-6-carbonitrile (7a) were prepared in moderate yields by cyanogen bromide-induced ring expansion of tetrahydrothieno [2,3- c] pyridinylalkanol precursors (4a) and (5a), respectively. 1-Phenyl-1,3,4,5,6,7-hexahydro[1]- benzothieno [3,2-g][1,4]oxazonine-5-carbonitrile (6b) and 1-phenyl-3,4,5,6,7,8-hexahydro-1H- [1] benzothieno [3,2-h][1,5]oxazecine-6-carbonitrie (7b) were similarly prepared from the [1] benzothieno [2,3-c] pyridinylalkanol precursors (4b) and (5b). The medium-ring cyanamides (6b) and (7b) were converted by standard methods into their N-methyl analogues (8b) and (9b). 6-Methyl-8-phenyl-4,5,6,8-tetrahydrothieno[3,2-e][1,2] oxazepine (13) was prepared by thermal Meisenheimer rearrangement of the corresponding tertiary amine N-oxide (12). The compounds (6a, b), (7a, b) and (13) are each the first reported examples of new heterocyclic systems. The crystal and molecular structure of (6b) has been determined by X-ray crystallographic methods.

The Reaction of 2-Hydro-2-oxo-5,6-benzo-l,3,2λ4-dioxaphosphorin-4-one with Imines and Carbonyl Compounds; Unusual Formation and First X-Ray Crystal Structure Determination of a Benzodioxaphosphepinone Ring System

1996 ◽  
Vol 51 (10) ◽  
pp. 1501-1510 ◽  
Author(s):  
Thomas Kaukorat ◽  
Ion Neda ◽  
Holger Thönnessen ◽  
Peter G. Jones ◽  
Reinhard Schmutzler
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Structure Determination ◽  
Ring Expansion ◽  
Ring System ◽  
Crystal Structure Determination ◽  
Insertion Reaction ◽  
X Ray ◽  
Ir Spectroscopic

On treatment of 2-hydro-2-oxo-5,6-benzo-1,3,2λ4-dioxaphosphorin-4-one (1) with the inline trimers trim ethyl- and tribenzyltriazine and the (monomeric) methylene-tert-butylimine, an insertion reaction of the imine molecule into the P-H bond of 1 took place, forming com pounds 2 -4 . Similar results were obtained when 1 was allowed to react with aldimines, asymmetric at carbon, leading to 5-7 . The diastereotopic properties of 5 - 7 were observed by 1H NMR spectroscopy. NMR and IR spectroscopic investigations on 5 - 7 indicated > C = O···H-N < interactions. Upon reaction of 1 with hexafluoroacetone, trifluoroacetophenone or phenyltrifluoromethylketimine, the derivatives 8 -1 0 , involving a P-O-C fragment, were obtained. The formation of the isomeric “alcohol form ”, bearing a P-C-OH fragment, could not be proved. In the reaction of 1 with various o-quinones. one of the oxygen atom s of the quinone was found to be bonded to phosphorus, whereas the hydrogen atom was found to migrate to the second oxygen atom . Upon reaction of 1 with chloral, an unusual ring expansion took place with formation of the benzodioxaphosphepinone (14). The reaction of 1 with other aldehydes could not be realized. In the reaction of 14 with triethylamine, the ammonium salt 15 was formed. For the first time, an X-ray crystal structure determination of a dioxaphosphepinone ring system was conducted; in 15 the seven-membered ring displays a pseudo tub conformation.

Tetrahydropyridine (THP) Ring Expansion under the Action of Activated Terminal Alkynes. The First Synthesis and X-Ray Crystal Structure of Tetrahydropyrimido[4,5-d]azocines.

ChemInform ◽  
2006 ◽  
Vol 37 (20) ◽  
Author(s):  
Leonid G. Voskressensky ◽  
Tatiana N. Borisova ◽  
Innokenti s. Kostenev ◽  
Larisa N. Kulikova ◽  
Alexey V. Varlamov
Keyword(s):  
Crystal Structure ◽  
Ring Expansion ◽  
Terminal Alkynes ◽  
X Ray
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