The invention relates to a method for producing a biomass-resource-derived polyurethane, which comprises: reacting a dicarboxylic acid and an aliphatic diol to produce a polyester polyol; and reacting the polyester polyol and a polyisocyanate compound, wherein the dicarboxylic acid contains at least one component derived from biomass resources, a content of an organic acid in the dicarboxylic acid is more than 0 ppm and not more than 1,000 ppm relative to the dicarboxylic acid, and a pKa value of the organic acid at 25 C. is not more than 3.7.

The invention relates to a method for producing a biomass-resource-derived polyurethane, which comprises: reacting a dicarboxylic acid and an aliphatic diol to produce a polyester polyol; and reacting the polyester polyol and a polyisocyanate compound, wherein the dicarboxylic acid contains at least one component derived from biomass resources, a content of an organic acid in the dicarboxylic acid is more than 0 ppm and not more than 1,000 ppm relative to the dicarboxylic acid, and a pKa value of the organic acid at 25 C. is not more than 3.7.

The invention relates to a method for producing a biomass-resource-derived polyurethane, which comprises: reacting a dicarboxylic acid and an aliphatic diol to produce a polyester polyol; and reacting the polyester polyol and a polyisocyanate compound, wherein the dicarboxylic acid contains at least one component derived from biomass resources, a content of an organic acid in the dicarboxylic acid is more than 0 ppm and not more than 1,000 ppm relative to the dicarboxylic acid, and a pKa value of the organic acid at 25 C. is not more than 3.7.

The invention relates to a method for producing a biomass-resource-derived polyurethane, which comprises: reacting a dicarboxylic acid and an aliphatic diol to produce a polyester polyol; and reacting the polyester polyol and a polyisocyanate compound, wherein the dicarboxylic acid contains at least one component derived from biomass resources, a content of an organic acid in the dicarboxylic acid is more than 0 ppm and not more than 1,000 ppm relative to the dicarboxylic acid, and a pKa value of the organic acid at 25 C. is not more than 3.7.

The invention relates to a method for producing a biomass-resource-derived polyurethane, which comprises: reacting a dicarboxylic acid and an aliphatic diol to produce a polyester polyol; and reacting the polyester polyol and a polyisocyanate compound, wherein the dicarboxylic acid contains at least one component derived from biomass resources, a content of an organic acid in the dicarboxylic acid is more than 0 ppm and not more than 1,000 ppm relative to the dicarboxylic acid, and a pKa value of the organic acid at 25 C. is not more than 3.7.

The present invention relates to the diastereomeric salts (Va), (Vb), (Vc) and/or (Vd), to a process for preparing the diastereomeric salts (Va), (Vb), (Vc) and/or (Vd) using a chiral substituted tartaric ester of the formula (IIIa) or (IIIb), to a process for preparing the compound of formula (IVa) using the diastereomeric salts (Va), (Vb), (Vc) and/or (Vd), to a process for preparing the compound of the formula (VIIa) using the diastereomeric salts (Va), (Vb), (Vc) and/or (Vd), to a process for preparing the compound of the formula (Ia) using the diastereomeric salts (Va), (Vb), (Vc) and/or (Vd), to the use of the diastereomeric salts (Va), (Vb), (Vc) and/or (Vd) for preparation of one of the compounds of formula (IVa), (VIIa) and/or (Ia), to the use of a chiral substituted tartaric esters of the formula (IIIa) or (IIIb) for preparation of the diastereomeric salts (Va), (Vb), (Vc) and/or (Vd), and to the use of a chiral substituted tartaric ester of the formula (IIIa) or (IIIb) for preparation of one of the compounds of formula (IVa), (VIIa) and/or (Ia).

The invention relates to a method for producing oxobutanol esters of polymeric carboxylic acids, especially 4-oxo-4-(C.sub.1-C.sub.5-alkoxy)-2-butanol esters or 4-oxo-4-(hydroxy-C.sub.3-C.sub.5-alkoxy)-2-butanol esters of polymeric carboxylic acids, as well as the products thus obtained and their use.

The invention relates to a method for producing oxobutanol esters of polymeric carboxylic acids, especially 4-oxo-4-(C.sub.1-C.sub.5-alkoxy)-2-butanol esters or 4-oxo-4-(hydroxy-C.sub.3-C.sub.5-alkoxy)-2-butanol esters of polymeric carboxylic acids, as well as the products thus obtained and their use.

The invention relates to a method for producing a biomass-resource-derived polyurethane, which comprises: reacting a dicarboxylic acid and an aliphatic diol to produce a polyester polyol; and reacting the polyester polyol and a polyisocyanate compound, wherein the dicarboxylic acid contains at least one component derived from biomass resources, a content of an organic acid in the dicarboxylic acid is more than 0 ppm and not more than 1,000 ppm relative to the dicarboxylic acid, and a pKa value of the organic acid at 25? C. is not more than 3.7.

The invention relates to a method for producing a biomass-resource-derived polyurethane, which comprises: reacting a dicarboxylic acid and an aliphatic diol to produce a polyester polyol; and reacting the polyester polyol and a polyisocyanate compound, wherein the dicarboxylic acid contains at least one component derived from biomass resources, a content of an organic acid in the dicarboxylic acid is more than 0 ppm and not more than 1,000 ppm relative to the dicarboxylic acid, and a pKa value of the organic acid at 25? C. is not more than 3.7.