Abstract: A method is provided for the preparation of high-purity 1,3-butylene glycol from acetaldehyde. In the method, acetaldehyde is condensed in the presence of base to form a mixture of acetaldols, and the acetaldols are then converted to 1,3-butylene glycol by hydrogenation. Chemical treatment and distillation processes are described which provide 1,3-butylene glycol of very high purity.

Abstract: A first invention group is characterized by 1,3-butylene glycol which, at a period of three months after production, exhibits potassium permanganate color-fading time of at least five minutes as measured according to JIS K1351 3.10.

Abstract: In a method of producing a dialdehyde monoacetal(s) (III) from dialdehyde(s) (I) and diol(s) (II), the present invention provides a method comprising a first step wherein said dialdehyde(s) (I) and said diol(s) (II) are reacted to produce dialdehyde bisacetal(s) (IV), the amount by mole of said diol(s) (II) being at least twice the amount by mole of said dialdehyde (I) and a second step wherein said dialdehyde bisacetal(s) (IV) is reacted with said dialdehyde (I). The present invention also provides a method of producing a glutaraldehyde monoacetal via reacting 2-Y-3, 4-dihydro-2H-pyran or a ring-substituted derivative thereof with diol. This method comprises a second step reaction wherein glutaraldehyde (iv) which is one of the by-products of the first step reaction is reacted with glutaraldehyde bisacetal (v) which is another by-product of said first reaction.