10097-02-6Relevant articles and documents
Ab initio structure determination of monoclinic 2,2-dihydroxymethylbutanoic acid from synchrotron radiation powder diffraction data: Combined use of direct methods and the Monte Carlo method
Tanahashi, Yusaku,Nakamura, Hisayoshi,Yamazaki, Satoru,Kojima, Yuko,Saito, Hideshi,Ida, Takashi,Toraya, Hideo
, p. 184 - 189 (2001)
The crystal structure of 2,2-dihydroxymethylbutanoic acid (C6H12O4) in monoclinic form has been determined ab initio from synchrotron radiation powder diffraction data. Two O and five C atoms were first derived by direct methods. Two missing O atoms and one C atom were found by the Monte Carlo method without applying constraint to their relative positions. Positional and isotropic displacement parameters of these non-H atoms were refined by the Rietveld method. Molecules are linked by hydrogen bonds and they make sheet-like networks running parallel to the (010) plane. The Monte Carlo method is demonstrated to be a powerful tool for finding missing atoms in partially solved structure.
Preparation method of 2,2-dimethylolbutyric acid
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Paragraph 0029-0041; 0043-0045, (2019/10/01)
The invention discloses a preparation method of 2,2-dimethylolbutyric acid; beta, beta-dihydroxymethyl butyraldehyde is produced by reaction of butyraldehyde and polyformaldehyde as raw materials under the action of an organic base catalyst, the beta, beta-dihydroxymethyl butyraldehyde is oxidized under the action of hydrogen peroxide to obtain beta, beta-dihydroxymethyl butyric acid, the beta, beta-dihydroxymethyl butyric acid is neutralized by an inorganic base to obtain beta, beta-dihydroxymethyl butyrate, and the beta, beta-dihydroxymethyl butyrate is distilled and filtered to obtain highpurity beta, beta-dihydroxymethyl butyrate, and finally, the 2,2-dimethylolbutyric acid is obtained by acidification of the high purity beta, beta-dihydroxymethyl butyrate under the action of an acid.The preparation method is characterized in that the 2,2-dimethylolbutyric acid is prepared by a new synthesis method, a recrystallization step in the traditional process is omitted, the reaction efficiency is high, the product is easy to separate, the yield of the product can be greatly improved, the waste is less, and the design idea of green chemistry is met.
Cosmetic or dermatological topical compositions comprising dendritic polyesters
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, (2008/06/13)
The present invention relates to cosmetic or dermatological compositions capable of being applied to the skin, the keratinous fibers, the nails, the semimucous membranes and/or the mucous membranes, and which includes a dendritic polyester polymer having terminal hydroxyl functional groups or the combination of such a polymer with a film-forming polymer. It also relates to methods of cosmetic or dermatological treatment using these compositions as well as the use of the compositions for the preparation of dermatological or cosmetic compositions.