Syntheses of the methyl glycosides of curacin, a-b fragment found in avilamycin-a and -c, curamycin-a, flambamycin and everninomicin-2, and of its artificial regioisomer isocuracin

✍ Scribed by Peter Jütten; Jürgen Dornhagen; Hans-Dieter Scharf

• Book ID: 104203016
• Publisher: Elsevier Science
• Year: 1987
• Tongue: French
• Weight: 534 KB
• Volume: 43
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)83453-0

✦ Synopsis

Absrrnct-Methyl 4-O-dichloroisoeveminyl-a-Darabino-hexopyranoside, the methyl glycoside of curacin, 2, which is the chromophoric A-B terminus of orthosomycins. was synthesiz.ed by esterification of methyl 3-O-bcnzyl-2,6didcoxy-a-D-arabino-hcxopyrosidc ( ) with 4-benzyloxy-3,5-dichloro-2-methoxy-6-methylbenzoyl chloride ( ) with the help of n-butyl lithium, followed by hydrogcnolytic debenzylation. The estcrificadon of methyl 2,6_dideoxy-a-D-arabino-hexopyranoside (8) with 4-benzyloxy-3.5dichloro-2-hydroxy-6mcthylbenzoic acid (13) in the presence of CBI/DBN afforded after mcthylation with diazomethane and hydrogenolytic debcnzylation the methyl glycoside of isocuracin, the artificial regioisomcr of curacin, 5. Derivatives of dichloroisoeverninic acid (10) decomposed under the reaction conditions of various estcrification methods.