- 1,3-butanediol synthesis method and system
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The invention discloses a 1,3-butanediol synthesis method and system. For the synthesis method, 1,3-butanediol is produced from acetaldehyde by a 2,6-dimethyl-1,3-dioxane-4-alcohol route; the stability of the intermediate product is improved; the selectivity of the 1,3-butanediol is improved; the generation of harmful, easy-color-developing and smelly crotonaldehyde and derivatives is reduced. Meanwhile, a tubular reactor with a built-in component is used as a condensation reactor; the heat can be effectively removed; the low-temperature cooling load is reduced; the reaction controllability isimproved; the unnecessary backmixing is reduced; the generation of by-products is reduced. The 2,6-dimethyl-1,3-dioxane-4-alcohol pyrolysis is performed in a mode of firstly performing low-temperature flash evaporation and then performing catalytic reaction distillation; the acetaldehyde is recovered; the raw material utilization rate is effectively improved; the yield of the final product is improved; the chromaticity and the odor can meet the requirements of most high-level application.
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Paragraph 0096; 0098; 0102; 0106; 0108; 0110; 0112; 0114
(2018/09/08)
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- CONVERSION OF ALCOHOLS TO LINEAR AND BRANCHED FUNCTIONALIZED ALKANES
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Embodiments herein concerns the eco-friendly conversion of simple alcohols to linear or branched functionalized alkanes, by integrated catalysis. The alcohols are firstlyoxidized either chemically or enzymatically to the corresponding aldehydes or ketones, followed by aldol condensations using a catalyst to give the corresponding enals or enones. The enals or enones are subsequently and selectively hydrogenated using a recyclable heterogeneous metal catalyst, organocatalyst or an enzyme to provide linear or branched functionalized alkanes with an aldehyde, keto- or alcohol functionality. The process is also iterative and can be further extended by repeating the above integrated catalysis for producing long-chain functionalized alkanes from simple alcohols.
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Page/Page column 9
(2018/03/09)
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- One-Pot Synthesis of (S)-Baclofen via Aldol Condensation of Acetaldehyde with Diphenylprolinol Silyl Ether Mediated Asymmetric Michael Reaction as a Key Step
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An efficient asymmetric total synthesis of (S)-baclofen was accomplished via a one-pot operation from commercially available materials using sequential reactions, such as aldol condensation of acetaldehyde, diphenylprolinol silyl ether mediated asymmetric Michael reaction of nitromethane, Kraus-Pinnick oxidation, and Raney Ni reduction. Highly enantioenriched baclofen was obtained in one pot with a good yield over four reactions.
- Hayashi, Yujiro,Sakamoto, Daisuke,Okamura, Daichi
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supporting information
p. 4 - 7
(2016/01/15)
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- REACTIONS OF PO(NCS)3 WITH 4-HYDROXY-1,3-DIOXANES. CRYSTAL STRUCTURE OF rel-(2S,4R,5S,6S)-2,6-DIETHYL-5-METHYL-4-(N'-BENZYLTHIOUREIDO)-1,3-DIOXANE
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Substituted 4-hydroxy-1,3-dioxanes II react rapidly with PO(NCS)3 to give 4-isothiocyanato-1,3-dioxanes III.The 1H NMR spectra showed that in the isothiocyanate IIIa the predominant stereoisomer has its NCS group in axial position.The addition of benzylamine to the isothiocyanates IIIa and IIIb gave uniform thioureas IVa and IVb with equatorial alkyl groups at 2 and 6 positions and axial thioureido group at the 4 position.On the other hand, the isothiocyanate IIIc reacts with benzylamine to give a mixture of three stereoisomeric thioureas V, VI, and VIII.The structure of VI was proved by means of X-ray diffraction analysis; in crystalline form the molecules of VI are present as H-bonded dimers (N-H...O).
- Bernat, Juraj,Kniezo, Ladislav,Birosova, Gabriela,Budesinsky, Milos,Podlaha, Jaroslav,et al.
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p. 1299 - 1313
(2007/10/02)
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