A method for the preparation of oxygen containing spirocycles using singlet oxygen is reported. A series of phenols were converted into the corresponding peroxy-cyclohexadienone derivatives by irradiation with visible light in the presence of a sensitizer and oxygen. The resulting peroxides could be converted into ether and lactone spirocycles in one or two steps. The synthesis of the oxaspirocycles from the phenols can also be performed in a one-pot fashion, avoiding the isolation of the peroxide intermediates. (C) 2013 Elsevier Ltd. All rights reserved.
research of C-H bond hydroxylation, we found that multi-alkyl phenols could react with molecular oxygen under mild conditions. Herein, we describe an efficient oxidative de-aromatization of multi-alkyl phenols to p-quinols. 1 atm of molecular oxygen was used as the oxidant. Many multi-alkyl phenols could react smoothly at room temperature. Isotopic labeling experiment was also performed, and the result
Methods for applying high shrink wrap labels to a shaped article are disclosed. The leading edge of the label is bonded to the article. A seaming agent is applied, and the label is wrapped around the article. The seaming agent is then exposed to radiation to cure the seaming agent, and the label is then exposed to heat to cause heat-shrinking. The label is made of a film with at least one external layer that has a Hildebrand solubility parameter. The seaming agent includes a component having a Hildebrand solubility parameter that is within 2.2 MPa1/2 or within 4.4 calories1/2·cm−3/2 of the Hildebrand solubility parameter of the external layer of the film. The seaming agent also has a viscosity of at least 1 centipoise and less than 1000 centipoise when measured at any temperature between ambient temperature and 60° C. Articles including such affixed high shrink wrap labels are also disclosed.