Carbonyl carbon, formation, deep

A more deep-seated change than decarboxylation can easily occur. You will remember that I have stressed all along that these carbonyl reactions are reversible, though we don t always show them as such. Even the format ion of carbon-carbon bonds is re vers ible. If we take some of this compound and treat it with EtO, will it form a substantial amount of enolate ... 

Cresol-formaldehyde, phenol-formaldehyde, and chlorinated cresol-formaldehyde novolac resins all undergo photo-oxidation upon UV-irradiation in air. The change of the carbon core level signals is shown in Fig. 8. The new IR band at about 1720 cm-, corresponding to formation of a carbonyl group, is also found after photo-oxidation of novolac resin. These oxidized layers of the novolac film are limited to a very shallow superficial surface only about 500 A thick, even after long deep UV irradiation, as discussed below in reference to photostabilization of resist images. 

---