Abstract: A process for preparing a butanetriol derivative of the formula (1) useful as intermediates of medicines wherein R1 is the same defined below, which comprises reacting a compound of the formula (3) wherein R1 and R2 are the different protecting groups, and an ethylene glycol derivative in a basic condition to prepare a compound of the formula (4) or (4a) wherein R1 and R2 are the same defined above, and then subjecting the compound (4) or (4a) to selective deprotection reaction.

Abstract: An object of the present invention is to provide a process wherein 1, 2,4-butanetriol can be obtained safely, easily and inexpensively without causing problems concerning wastewater. A malic diester, 3-hydroxy-&ggr;-butyrolactone or 3,4-dihydroxybutanoate represented by the following formulae (I), or a mixture thereof is reduced with sodium borohydride in an organic solvent to give 1,2,4-butanetriol represented by the following formula (II). When an optically active substance is used as the above-mentioned starting compound, substantially no recemization occurs during the reduction, and optically active 1,2,4-butanetriol is obtained.

Abstract: A method for processing a solution of ethylene-vinyl alcohol copolymer in a solvent other than water, which involves continuously substituting a part of the solvent in the solution with water to produce a high-concentration ethylene vinyl alcohol copolymer solution without gelling, whereby an ethylene-vinyl alcohol copolymer solution is fed into a column vessel selected from a plate column and a packed column, and a part of the solvent in the solution is substituted with water in the column vessel.

Abstract: The present invention provides a process for obtaining 1,2-propanediol or optically active substances thereof in high yields and at a low cost using readily available starting materials. According to the process of the present invention, 3-halogeno-1,2-propanediol of the general formula [I] is catalytically hydrogenated in an alcoholic solvent having two or more carbon atoms in the presence of a base of an equivalent or less to the starting material to give 1,2-propanediol of the formula [II]. In the formula [I], X stands for a halogen atom.

Abstract: A process for preparation of a glycidyl ether which is characrelized in reacting an epoxy compound of the formula ##STR1## wherein X is halogen or sulfonyloxy in the presence of a fluoride salt, with an alcohol. According to the above method, glycigyl ethers or their optically active compounds important as intermediates for synthesis of medicines are easily obtained in good yield and especially the optically active compounds are obtained with highly optical purity.

Abstract: A process for preparation of 3-amino-2-hydroxy-1-propyl ether of the formula ##STR1## wherein R.sup.1 is substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heterocyclic ring, R.sup.2 and R.sup.3 are the same or different hydrogen atom, a substituted or unsubstituted alkyl, or may form a ring together with an adjacent nitrogen atom, which ring may be interrupted with nitrogen atom, oxygen atom or sulfur atom,which is characterized in reacting an epoxy compound of the formula ##STR2## wherein X is halogen, in the presence of a fluoride salt, with an alcohol and then reacting an amine.According to the above method, an intermediates for synthesis of medicines is obtained in good yield and highly optical purity.

Abstract: The present invention provides a cyclic sulfide compound represented by a general formula (I) ##STR1## (where R.sup.1 represents --CH.sub.2 --CH.sub.2 --, --CH.sub.2 --CH.sub.2 --CH.sub.2 --, --CH.sub.2 --O--CH.sub.2 --, --CH.sub.2 --O--, or --CH.sub.2 --S--). According to this invention, a novel cyclic sulfide compound which gives high refractive index and high Abbe number can be obtained. The polymerizable compositions for manufacturing optical products with this compound as their main component can be readily molded into plastic lenses which give superhigh refractive indices and high Abbe numbers or those which give high refractive indices and high Abbe number with low sp.grs. in addition thereto. The castings obtained from said polymerizable compositions are useful as plastic lenses for glasses, manifesting optical uniformity and being excellent in processability, transparency, and thermal, impact and light resistance.

Abstract: The present invention provides a cyclic sulfide compound represented by a general formula (I) ##STR1## (where R.sup.1 represents --CH.sub.2 --CH.sub.2 --, --CH.sub.2 --CH.sub.2 --CH.sub.2 --, --CH.sub.2 --O--CH.sub.2 --, --CH.sub.2 --O--, or --CH.sub.2 --S--). Polymerizable compositions for manufacturing optical products with this compound as their main component can be readily molded into plastic lenses which give superhigh refractive indices and high Abbe numbers or those which give high refractive indices and high Abbe number with low sp.grs. in addition thereto. The castings obtained from said polymerizable compositions are useful as plastic lenses for glasses, manifesting optical uniformity and being excellent in processability, transparency, and thermal, impact and light resistance. Further these polymerizable resin compositions are usable preferably as such optical products as prisms, optical fibers, optical disc substrates, color filters, or infrared absorption filters.