Browsing by Author "Manabe, Yoshiyuki"

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Flow Dehydration and Hydrogenation of Allylic Alcohols: Application to the Waste-Free Synthesis of Pristane
(2017-03-10)
Furuta, Akihiro
;
Hirobe, Yuki
;
Fukuyama, Takahide
;
Ryu, Ilhyong
;
Manabe, Yoshiyuki
Hydroxy-substituted sulfonic acid functionalized silica (HO-SAS) in combination with THF containing a small amount of water as a solvent proved to be a reliable system for the dehydration of allylic alcohols. This process generally caused dehydration within 1 min through a column reactor charged with HO-SAS. The flow dehydration was sequenced by flow hydrogenation, which resulted in the synthesis of pristane. A scalable flow synthesis of pristane was successfully performed and afforded 10 g of pristane after an operation of 2 h. We also performed dehydration and hydrogenation by using a mixed column of HO-SAS and 10 % Pd/C.
Single-Step Per-O-Sulfonation of Sugar Oligomers with Concomitant 1,6-Anhydro Bridge Formation for Binding Fibroblast Growth Factors
(2019-01-18)
Yeh, Che-Jui
;
Ku, Chiao-Chu
;
Lin, Wei-Chen
;
Fan, Chiao-Yuan
;
Zulueta, Medel Manuel L.
Many circulating cancer-related proteins, such as fibroblast growth factors (FGFs), associate with glycosaminoglycans-particularly heparan sulfate-at the cell surface. Disaccharide analogues of heparan sulfate had previously been identified as the shortest components out of the sugars that bind to FGF-1 and FGF-2. Taking note of the typical pose of l-iduronic acid, we conceived of per-O-sulfonated analogues of such disaccharides, and devised a single-step procedure for per-O-sulfonation of unprotected sugars with concomitant 1,6-anhydro bridge formation to achieve such compounds through direct use of SO3Et3N as sulfonation reagent and dimethylformamide as solvent. The synthesized sugars based on the oligomaltose backbone bound FGF-1 and FGF-2 mostly at the sub-micromolar level, although the tetrasaccharide analogue achieved low-nanomolar binding with FGF-2.