Abstract: The invention relates to a process for preparing chiral imidazolidin-2-ones of the formula I in which R1 is C1-C8-alkyl, cyclohexyl, phenyl, a C1-C6-alkyl-, halo-, nitro-, C1-C6-alkoxy-, C1-C6-alkylmercapto- or CF3-substituted phenyl radical, naphthyl or a C1-C6-alkyl-, halo-, nitro-, C1-C6-alkoxy- or CF3-substituted naphthyl radical, R2 is C1-C8-alkyl, C2-C8-alkenyl, cyclohexyl, phenyl or a phenyl-C1-C6-alkyl radical which may be substituted by a nitro, C1-C6-alkoxy, methylenedioxy or CF3 radical, and R3 is C1-C12-alkyl, C2-C8-alkenyl, cyclohexyl, phenyl or a C1-C6-alkyl-, halo-, nitro-, C1-C6-alkoxy-, methylenedioxy-, dialkylamino- or CF3-substituted phenyl radical, by reacting a compound of the formula II or the salt thereof in which R1, R2 and R3 have the abovementioned meaning, with urea in the presence of an involatile ammonium salt, wherein the reaction is carried out in the presence of an aprotic polar organic solvent.

Abstract: The invention relates to a process for preparing chiral imidazolidin-2-ones of the formula I in which R1 is C1-C8-alkyl, cyclohexyl, phenyl, a C1-C6-alkyl-, halo-, nitro-, C1-C6-alkoxy-, C1-C6-alkylmercapto- or CF3-substituted phenyl radical, naphthyl or a C1-C6-alkyl-, halo-, nitro-, C1-C6-alkoxy- or CF3-substituted naphthyl radical, R2 is C1-C8-alkyl, C2-C8-alkenyl, cyclohexyl, phenyl or a phenyl-C1-C6-alkyl radical which may be substituted by a nitro, C1-C6-alkoxy, methylenedioxy or CF3 radical, and R3 is C1-C12-alkyl, C2-C8-alkenyl, cyclohexyl, phenyl or a C1-C6-alkyl-, halo-, nitro-, C1-C6-alkoxy-, methylenedioxy-, dialkylamino- or CF3-substituted phenyl radical, by reacting a compound of the formula II or the salt thereof in which R1, R2 and R3 have the abovementioned meaning, with urea in the presence of an involatile ammonium salt, wherein the reaction is carried out in the presence of an aprotic polar organic solvent.

Abstract: The invention relates to a process for the preparation of cis-6-hexadecenoic acid of the formula I, which comprises reacting a1) a triphenylphosphonium salt of the formula II, R1OOC—(CH2)5—P(R2)3+X−  II  with decanal of the formula III H3C—(CH2)8—CH═O  III  or a2) a triphenylphosphonium salt of the formula IV, H3C—(CH2)9—P(R2)3+X−  IV  with an aldehyde of the formula V, R1OOC—(CH2)4—CH═O  V  in a Wittig reaction, and b) saponifying the ester, formed by process step a1) or a2), of the formula VI,  where the substituents R1, R2 and X− have the meanings given in the description.

Abstract: A process for preparing high-purity phytantriol, that includes rectifying the phytantriol which is obtained and is contaminated with lower and/or higher boiling byproducts under medium vacuum in rectification columns containing metal cloth packings with ordered structure using channel liquid distributors with a minimum of 500 drip points/m2, which are arranged at an angle of 90° to the cloth layers of the packing elements located directly below the distributors, in which 2 or more of the packing elements underneath the liquid distributors have only a small height, which ensure absolute exclusion of air and a strictly adiabatic procedure. The preparation of high-purity phytantriol takes place particularly advantageously when the phytantriol which is contaminated with byproducts is a phytantriol which has been obtained by reacting isophytol with performic acid and subsequently hydrolyzing the product formed in the reaction with alkaline agents in a manner known per se.

Abstract: The invention relates to a process for the preparation of cis-6-hexadecenoic acid of the formula I, 1