Abstract: This invention provides a process for preparing 2-oxycephalosporin derivative represented by the formula ##STR1## wherein R.sup.1 represents hydrogen atom, acyl group, or lower alkoxycarbonyl group optionally substituted with halogen atom, R.sup.2 represents hydrogen atom, halogen atom or acyloxy group optionally substituted with halogen atom, R.sup.3 represents hydrogen atom, lower alkyl group optionally substituted with halogen atom, or phenyl-lower alkyl group which may be optionally substituted with nitro group, halogen atom or lower alkoxy group on the phenyl ring, and R.sup.4 represents lower primary or secondary alkyl or lower alkylcarbonyl, the process comprising electrolytically oxidizing a cephalosporin derivative represented by the formula ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above, in the presence of a lower carboxylic acid or lower primary or secondary alcohol, and a supporting electrolyte.

Abstract: This invention provides a process for preparing a thiazolinoazetidinone derivative represented by the formula ##STR1## wherein R.sup.1 represents aralkyl group or aryloxymethyl group and R.sup.2 represents acyl group, the process comprising electrolyzing a compound of the formula ##STR2## wherein R.sup.1 is as defined above in the presence of a lower fatty acid.

Abstract: This invention provides a process for preparing an oxazolineazetidinone derivative represented by the formula ##STR1## (wherein R.sup.1 represents hydrogen atom, alkyl group, alkenyl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted aryl group, or substituted or unsubstituted aryloxymethyl group, R.sup.2 represents free or protected carboxyl group and R.sup.3 represents hydrogen atom or methoxy group) from a penicillin derivative represented by the formula ##STR2## wherein R.sup.1, R.sup.2 and R.sub.3 are as defined above.

Abstract: A composition useful for inhibiting adhesion and propagation of undesirable algae and/or shellfish on articles, which comprises triisobutyltin hydroxide, an arylsulfonic acid derivative and an organic solvent. The composition may further comprise a phenol substituted by an alkyl radical and a chlorine atom and/or a pyridazine derivative. A method of using the composition is also disclosed.