Carbene-complex-promoted ring expansion of aziridine: formation of the 1-azabicyclo[4.3.0] ring system by a double alkyne and a single carbon monoxide insertion reaction

1988 ◽  
pp. 1303 ◽  
Author(s):  
Bernard Denise ◽  
Andrei Parlier ◽  
Henri Rudler ◽  
Jacqueline Vaissermann ◽  
J. C. Daran
Keyword(s):  
Carbon Monoxide ◽  
Ring Expansion ◽  
Ring System ◽  
Insertion Reaction ◽  
Carbene Complex

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.

Carbodiimide insertion into sulfonimides: one-step route to azepine derivatives via a two-atom saccharin ring expansion

2017 ◽  
Vol 53 (5) ◽  
pp. 901-904 ◽  
Author(s):  
Davin Tan ◽  
Tomislav Friščić
Keyword(s):  
Ring Expansion ◽  
Insertion Reaction ◽  
Direct Expansion ◽  
One Step

A novel carbodiimide insertion reaction enables a one-step, two-atom expansion of cyclic and linear sulfonimides, including the first direct expansion of saccharin into thiadiazepines.

Synthetic studies related to mycobactins. III. Approaches to the synthesis of the cobactin ring system

1972 ◽  
Vol 25 (11) ◽  
pp. 2429 ◽  
Author(s):  
DSC Black ◽  
RFC Brown ◽  
AM Wade
Keyword(s):  
Primary Amine ◽  
Ring Expansion ◽  
Hydroxamic Acids ◽  
Ring System ◽  
Ethyl Benzoate ◽  
Yield Reduction ◽  
Similar Reaction ◽  
Oxidation Reactions ◽  
Cyclic Hydroxamic Acids ◽  
Synthetic Studies

The synthesis of several seven-membered cyclic hydroxamic acids has been carried out in low yield. Reduction of diethyl 2-hydroxyiminoheptane-l,7-dioate afforded ethyl 1-hydroxy-7-oxohexahydroazepine-2-carboxylate, together with related acyclic products. The cobactin precursor 3-bromo-1-hydroxyhexahydro-azepin-2-one was obtained by the ring expansion of 2-bromocyclohexanone with benzenesulphonohydroxamic acid and also by the peracid oxidation of 6-bromo-7-ethoxy-3,4,5,6-tetrahydro-2H-azepine. The methyl and cinnamyl imidates of hexanolactam were oxidized by peracid to 1-hydroxyhexahydroazepin-2-one, in addition to the related imino- and nitroso-hexanoic esters. In a similar reaction, 1-hydroxypiperidin-2-one was obtained from 2-methoxy-3,4,5,6-tetrahydropyridine. During the course of these oxidation reactions, the intermediate oxaziridines 7-methoxy-8-oxa-1-azabicyclo[5,1,0]octane and 6-bromo-7-ethoxy-8-oxa-1-azabicyclo[5,1,0]octane were isolated and identified. The peraoid oxidation of ethyl N-cyclohexylbenzimidate yielded cyclohexylhydroxylamine and ethyl benzoate in reasonable yields. This reaction suggests a useful method for the conversion of a primary amine into the related hydroxylamine.

A stereocontrolled, enantiomerically specific total synthesis of thienamycin

1980 ◽  
Vol 289 (1036) ◽  
pp. 191-195 ◽  
Keyword(s):  
Total Synthesis ◽  
Aspartic Acid ◽  
Ring System ◽  
Insertion Reaction ◽  
Carbene Insertion ◽  
Metal Catalyzed

A versatile stereocontrolled total synthesis of thienamycin starting from L-aspartic acid is reported. Stereocontrol is achieved by potassium tri- sec -butylborohydride reduction of a thermodynamically formed 3α-acetylazetidinone intermediate. The key [3.2.0] bicyclic ring system is prepared by a metal catalyzed carbene insertion reaction.

Claisen Ring Expansion Approach toward the CDEF Ring System of Lancifodilactone G

Heterocycles ◽  
2009 ◽  
Vol 79 (1) ◽  
pp. 299 ◽  
Author(s):  
Leo A. Paquette ◽  
Kwong Wah Lai
Keyword(s):  
Ring Expansion ◽  
Ring System

scholarly journals Synthesis of a New Type of Trans-Decalin Vitamin D Analogue through a Dyotropic Ring Expansion

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Hugo Santalla ◽  
Uxía Gómez-Bouzó ◽  
Irene Sánchez-Sanz ◽  
Yagamare Fall
Keyword(s):  
Vitamin D ◽  
Research Group ◽  
Ring Expansion ◽  
Ring System ◽  
Side Chain ◽  
Sulphur Atom ◽  
Mild Conditions ◽  
New Type ◽  
Vitamin D Analogue

A new vitamin D analogue with a trans-fused decalin as the CD-ring system and containing a sulphur atom in the side chain has been synthesized in our research group. The obtention of this analogue is based on a recently discovered transformation of hydrindane cores into decalins through a dyotropic ring expansion in very mild conditions.

ChemInform Abstract: KINETIC AND THERMODYNAMIC CONTROL OF THE METHYL MIGRATION (CARBON MONOXIDE INSERTION) REACTION BY STRONG LEWIS ACIDS

1980 ◽  
Vol 11 (1) ◽  
Author(s):  
S. B. BUTTS ◽  
E. M. HOLT ◽  
S. H. STRAUSS ◽  
N. W. ALCOCK ◽  
R. E. STIMSON ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Lewis Acids ◽  
Insertion Reaction ◽  
Thermodynamic Control
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