Elimination Carbon monoxide

Interestingly, in the inverse-electron-demand Diels-Alder reactions of oxepin with various enophiles such as cyclopentadienones and tetrazines the oxepin form, rather than the benzene oxide, undergoes the cycloaddition.234 236 Usually, the central C-C double bond acts as dienophile. Oxepin reacts with 2,5-dimethyl-3,4-diphenylcyclopenta-2,4-dienone to give the cycloadduct 6 across the 4,5-C-C double bond of the heterocycle.234 The adduct resists thermal carbon monoxide elimination but undergoes cycloreversion to oxepin and the cyclopenta-dienone.234... 

Carbon monoxide elimination is observed when the bicyclic compounds of type IX/24 decompose [8]. Depending on the nature of the substituents at the bicyclic intermediate, IX/24 is more or less stable. Compound IX/24 and its dihydroderivative can be prepared by Diels-Alder reaction of a cyclopentadie-... 

Pace, N., Stajman, E., Walker, E.L. (1950). Acceleration of carbon monoxide elimination in man by high pressure oxygen. Science 111 652-4. 

Photolysis of difluoro(fluorosulfonyl)acctyl chloride takes place with elimination of carbon monoxide to give chlorodifluoromethanesulfonyl fluoride (6).124 Photolytic carbon monoxide elimination also occurs with the corresponding acetyl bromides and iodides. 

The substitution pattern of the cyclopentenones requires the loss of the oxo group rather than of the carbonyl of the carboxyl group. The mechanism is believed to consist of the formation of an acylketene with subsequent thermally allowed tc 2s -f tc 2a electrocyclic reaction leading to an intermediate cyclopropanone which then undergoes carbon monoxide elimination ... 

For the photochemical ring contraction of cyclobutane-1,2-diones with carbon monoxide elimination, see Section 4.1.1. 

More esoteric experimental procedures which can be applied to complex molecules include, for example, picosecond time-resolved circular dichroism. A spectrometer for this purpose has been described and used to observe carbon monoxide elimination from excited carbon raonoxymyoglobulin.Fluorescence detected CD has also been used to observe riboflavin in capillary electrophoresis. 

Cvetkovic, N., B. Adnajevic, and M. Nikohc Carbon monoxide elimination from tobacco smoke 2000 CORESTA Congress, Lisbon, Portugal, CORESTA Inf. BuU., 2000 Spec. Edition Paper STPOSTl 1, p. 214. 

Decarbonylation s. Carbon monoxide, elimination Decarboxylation HGfhC... 

S.3.3 Carbon Monoxide Elimination after Alpha Cleavage... 

FIGURE 9.43 Carbon monoxide elimination following cleavage in a of a carbonyl group. 

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