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Electroorganic Synthesis, 62!! Anodic Heterocoupling (Mixed Kolbe Electrolysis) of Carbohydrate Carboxylic Acids with Alkanoic Acids to C ‐Glycosides
Author(s) -
Harenbrock Michael,
Matzeit Agnes,
Schäfer Hans J.
Publication year - 1996
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.199619960109
Subject(s) - chemistry , glycoside , carbohydrate , platinum , methanol , yield (engineering) , galactose , electrolysis , organic chemistry , medicinal chemistry , electrode , electrolyte , catalysis , materials science , metallurgy
2‐Deoxy carbohydrate carboxylic acids 1–3 were prepared from glucal 4 , acetobromoglucose 5 , and D ‐galactose ( 7 ), respectively. The acids 1–3 were electrolyzed with different coacids at controlled current in methanol at platinum electrodes in an undivided cell to afford C ‐glycosides as heterocoupling products in 46–70% yield. Compound 28 , obtained by deacylation of 17 , has a critical micelle concentration (cmc) of 2.4 m M , which is about 2.5 times lower than that of the corresponding O ‐glycoside 29 . Compound 28 forms liquid crystals with a smectic A phase in the range between 96 and 190°C, which is twice as large as that of 29 . Compounds 31 and 32 , obtained by deprotection of 23 and 24 , respectively, also exhibit liquid crystalline behavior.