Abstract: Disclosed herein is method for producing an iron dinuclear complex having two iron atoms bonded to each other via one oxygen atom and a ligand structure containing a Schiff base, a method which can produce an ester compound in high yield by the transesterification of an alcohol compound with a carboxylate ester even in the case where the raw material alcohol has a tertiary hydroxyl group which is usually difficult to esterify by transesterification, and a method which can produce a wholly esterified compound by transesterification catalyzed by an iron complex.

Abstract: Disclosed herein is method for producing an iron dinuclear complex having two iron atoms bonded to each other via one oxygen atom and a ligand structure containing a Schiff base, a method which can produce an ester compound in high yield by the transesterification of an alcohol compound with a carboxylate ester even in the case where the raw material alcohol has a tertiary hydroxyl group which is usually difficult to esterify by transesterification, and a method which can produce a wholly esterified compound by transesterification catalyzed by an iron complex.

Abstract: An object of the invention is to provide a method for producing a (meth)acrylate ester compound by the transesterification of an alkyl (meth)acrylate with an alcohol compound having a tertiary hydroxyl group so as to esterify all the hydroxyl groups present in the alcohol compound with a high yield or, in a preferred embodiment, a method for esterifying a polyhydric alcohol compound having a tertiary hydroxyl group and also having a primary hydroxyl group and/or a secondary hydroxyl group by one-pot transesterification into a (meth)acrylate ester compound of the polyhydric alcohol. The method for producing a (meth)acrylate ester compound includes a step (I) of transesterifying an alkyl (meth)acrylate with an alcohol compound having a tertiary hydroxyl group using a transesterification catalyst including a complex of iron with a specific ligand, the water content in the transesterification reaction system being not more than 1000 ppm.

Abstract: The present invention provides a process for producing canthaxanthin by mixing &bgr;-carotene with an alkali metal chlorate or an alkali metal bromate in water and an organic solvent immiscible with water; adding an iodine halide or iodide; and adding a metal iodide whereby the &bgr;-carotene is oxidized to yield canthaxanthin.

Abstract: Antiviral agents comprising, as an active ingredient, a 1,4-dihydro-2,3-benzodithiin derivative of the formula ##STR1## wherein each symbol is as defined in the Specification, or a pharmacologically acceptable salt thereof. The antiviral agents of the present invention have superior antiviral activity and are effective for the preventive and therapeutic treatment of viral diseases caused typically by RS virus.