Enantiomeric synthesis of polyhydroxylated indolizidine analogues related to castanospermine: 1-deoxy-7-epicastanospermine and 1,7-dideoxy-7-fluorocastanospermine

✍ Scribed by C.-Kuan Lee; K.Y. Sim; Jun Zhu

• Publisher: Elsevier Science
• Year: 1992
• Tongue: French
• Weight: 309 KB
• Volume: 48
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)86601-1

✦ Synopsis

Trihydroxyindolizidine (1) and its (7R)-deoxyfh~on~ analogue (2) was synthesised from 5,8-benzyloxycarbonylimino-5.6,7,8-tetradeoxy-l,2-0-isopropylidene-a-D-gluco-octose (3). The key step is an oxidation-reduction sequence. Introduction of a fluoro substituent at C-3 (6) was readily effected by displacement of the 3-trifluoromethanesulfonyl (triflate) group with tris-(dimethylamino)-sulfoniumdifluorotrimethylsilicate (TASK).