Carbon dioxide compounds acyclic

The acyclic compound l-NaphPh(H)SiOCOPh is not significantly converted to benzaldehyde on thermolysis, even at temperatures considerably higher than those (100-160 °C) which are effective with the chelate system. This reaction may proceed via the transient formation of a chelated silanone 82, since the trisiloxane 80 is isolated as the silicon-containing product. Confirmation of this mechanism was obtained in the reaction of 78 with carbon dioxide, from which the silyl ester of formic acid 81 can be isolated and... 

More than a dozen oxides of sulfur are known, but some of them are rather unimportant cyclic monoxides formed by treating a puckered ring of 5 to 10 sulfur atoms with a per-oxy acid, and others are unstable acyclic species. Two of the acyclic oxides, however, are extremely important sulfur dioxide (SO2) and sulfur trioxide (SO3). In the decade of the 1980s, when acid rain became a household word, these two compounds and their roles in acid rain formation became as familiar to the educated laity as carbon monoxide and carbon dioxide. 

Diazoalkanes add to the carbon-carbon double bonds of 2,3-diphenylthiirene 1-oxide and 1,1-dioxide. The adducts lose SO or SO2 to give pyrazoles and related compounds (Scheme 103) (80CB1632). Mesoionic oxazolones (75CLH53), 4-methyl-5-phenyl-l,2-dithiolene-3-thione (80JOU395) and pyrylium betaines (72JOC3838) react similarly via intermediate adducts (Scheme 104). Enamines (Scheme 96) and ynamines add to the double bond of 2,3-diarylthiirene 1,1-dioxides to give acyclic and cyclic sulfones by a thermal. 

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