- Switching chirality in the assemblies of bio-based amphiphiles solely by varying their alkyl chain length
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Here we show that chirality inversion can be realized solely by changing the alkyl chain length of sorbitol-alkylamine surfactants. The chirality switch phenomenon is attributed to twisting of a headgroup, which depends on the balance between hydrophobic interaction and torsional stress, resulting in various orientational orders in assemblies and chirality inversion.
- Zhang, Pei,Ma, Jun,Kang, Xinchen,Liu, Huizhen,Chen, Chunjun,Zhang, Zhanrong,Zhang, Jianling,Han, Buxing
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supporting information
p. 2162 - 2165
(2017/02/19)
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- Application of cation exchange resin to improvement of yield in bromination reaction of hexanehexol
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The invention relates to an application of cation exchange resin to a bromination reaction of hexanehexol. Yield of dibromohexanehexol is substantially increased in the preparation processes of dibromohexanehexol from hexanehexol by using the cation exchange resin, and the effects are obviously better than the effects in the prior art.
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Paragraph 0084 - 0089
(2017/07/08)
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- Short and efficient synthesis of polyhydroxylated tetrahydrothiophene, tetrahydrothiopyrane and thiepane from bielectrophilic erythro, threo, xylo, ribo, arabino, manno and gluco α,ω-dibromoalditol derivatives
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Polyhydroxylated tetrahydrothiophene, tetrahydrothiopyrane and thiepane rings have been readily obtained in excellent yields (78-95%) from thioheterocyclisation of the bielectrophilic peracetylated α,ω-dibrominated derivatives of tetritols (erythritol (1) and d,L-threitol (4)), pentitols (xylitol (7), ribitol (10) and D-arabinitol (14)) and hexitols (D-mannitol (17) and D-glucitol (20)), respectively. With 2,3,4,5-tetra-O-acetyl-1,6-dibromo-1,6-dideoxy-D-glucitol (21) as substrate, the unexpected 2,6-anhydro derivative 25 was obtained. This could be attributed to previous S= regioselective nucleophilic attack at C-1 position followed by 1,2-transesterification and 2,6-O-heterocyclisation. The preferential attack at C-1 of the D-glucitol derivative 21 subsequently allowed a facile direct synthesis in good yields of 2,3,4,5,6-penta-O-acetyl-1-bromo-1-deoxy-D-glucitol (26), 2,3,4,5-tetra-O-acetyl-6-bromo-6-deoxy-1-thiobutyl-1-deoxy-D-glucitol (28) and 2,3,4,5-tetra-O-acetyl-6-bromo-6-deoxy-1-thiooctyl-1-deoxy-D-glucitol (28).
- Halila, Sami,Benazza, Mohammed,Demailly, Gilles
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p. 3307 - 3310
(2007/10/03)
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