Abstract: In order to subject a cellulosic material such as insulating paper onto and into which transformer high-voltage insulating oil containing PCB has adhered and permeated to washing that removes the PCB etc. to an undetectable value, the cellulosic material to which PCB etc. has adhered is placed in DMI, sulfolane or other aprotic solvent containing an alkali such as caustic soda and stirred.

Abstract: A safe and reliable method of decomposing halogenated aromatic compounds, wherein a heat-resistant alkaline polar solvent containing halogenated aromatic compounds is contacted with a alkali at a temperature ranging from about 100.degree. C. to 300.degree. C. in order to decompose the halogenated aromatic compounds. The used solvent is removed of solid contents of salts, alkalis and the like, whereby it can be recycled.

Abstract: A safe and reliable method of removing halogenated aromatic compounds present in small amounts in hydrocarbon oil constituted mainly by non-aromatic hydrocarbon oil. The hydrocarbon oil is contacted with a heat-resistant alkaline polar solvent in the presence of an alkaline at a temperature ranging from about 100.degree. C. to 300.degree. C., and the non-aromatic hydrocarbon oil and heat-resistant alkaline polar solvent are then separated, thereby removing the halogenated aromatic compounds from the hydrocarbon oil.

Abstract: A beta-lactam compound of the formula: ##STR1## wherein R.sub.1 is a hydrogen atom, a lower alkyl group or a 1-hydroxy(lower)alkyl group wherein the hydroxyl group is optionally protected, R.sub.2 is a hydrogen atom or a protective group for the nitrogen atom and R.sub.3 is a methyl group, a halomethyl group, a hydroxymethyl group, a protected hydroxymethyl group, a formyl group, a carboxyl group, a lower alkoxycarbonyl group or an ar(lower)alkoxycarbonyl group wherein the aryl group is optionally substituted, or R.sub.2 and R.sub.3 are combined together to form an oxaalkylene group and, when taken together with one nitrogen atom and two carbon atoms adjacent thereto, they represent a six-membered cyclic aminoacetal group, which is useful as a valuable intermediate in the stereospecific production of 1-methylcarbapenem compounds.

Abstract: A beta-lactam compound of the formula: ##STR1## wherein R.sub.1 is a hydrogen atom, a lower alkyl group or a 1-hydroxy(lower)alkyl group wherein the hydroxyl group is optionally protected, R.sub.2 is a hydrogen atom or a protective group for the nitrogen atom and R.sub.3 is a methyl group, a halomethyl group, a hydroxymethyl group, a protected hydroxymethyl group, a formyl group, a carboxyl group, a lower alkoxycarbonyl group or an ar(lower)alkoxycarbonyl group wherein the aryl group is optionally substituted, or R.sub.2 and R.sub.3 are combined together to form an oxaalkylene group and, when taken together with one nitrogen atom and two carbon atoms adjacent thereto, they represent a six-membered cyclic aminoacetal group, which is useful as a valuable intermediate in the stereospecific production of 1-methylcarbapenem compounds.