- CHIMIE DES SUCRES SANS GROUPEMENTS PROTECTEURS-I-ESTERIFICATION REGIOSELECTIVE DE L'HYDROXYLE ANOMERE DU LACTOSE, DU MALTOSE ET DU GLUCOSE
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Treatment of acyl chlorides 4 with mercaptothiazoline, mercaptobenzothiazole, p-nitrophenol and 8-hydroxyquinoline in the presence of Et3N, afforded high yields of the corresponding reactive amides 5a-h,S-thioesters 6e-h and aryl esters 7e-h and 8a-h, respectively.The esters 6e-h, 7e-h and 8e-h reacted with excess β-lactose in pyridine, to give the corresponding β-esters 9e-h resulting from esterification of the anomeric hydroxyl of the sugar.The amides 5c, f-h gave the α-lactosyl esters 9c, f-h.The amide 5e and the esters 8b, c, e reacted with β-maltose, thus affording the corresponding β-maltosyl esters 10b, c, e, whereas the compounds 8a-e reacted with β-glucose, yielding the corresponding β-glucosyl esters 11a-e.This appears to be one of the very few selective chemical modifications of sugars known, which do not involve the toilsome protection-deprotection methology.The now commercially available maltosyl and glucosyl esters 10e and 11d-e are new non-ionic, and water soluble detergents which could be used for studies of cell membrane proteins.
- Plusquellec, Daniel,Roulleau, Fabienne,Bertho, Francoise,Lefeuvre, Martine,Brown, Eric
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p. 2457 - 2468
(2007/10/02)
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- CHIMIE DES SUCRES SANS GROUPEMENTS PROTECTEURS: ESTERIFICATION REGIOSELECTIVE DE L'HYDROXYLE ANOMERE DU LACTOSE LIBRE
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Treatment of α-lactose with acyl chlorides failed to give any pure products.However, the anomeric hydroxyl of lactose was esterified selectively and in high yields, by treating the free sugar with reactive acylating agents such as N-acyl thiazolidine-thiones or esters of p-nitrophenol, mercapto-benzothiazole and 8-hydroxy quinoline, making thus unnecessary the preliminary protection of the other hydroxyls of the lactose molecule.This appears to be one of the very few selective modifications of sugars known, which do not involve the classical protection-deprotection methodology.
- Roulleau, Fabienne,Plusquellec, Daniel,Brown, Eric
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p. 719 - 722
(2007/10/02)
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