Dithionite-Catalysed Addition of Perfluoroalkyl Iodides to Unsaturated Carbohydrates

✍ Scribed by Cornelia Zur; Ralf Miethchen

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 537 KB
• Volume: 1998
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199803)1998:3<531::aid-ejoc531>3.0.co;2-e

✦ Synopsis

The perfluoroalkyl chains (ϪC 4 F 9 , ϪC 6 F 13 , ϪC 8 F 17 ) were ter-Compounds 9, 10, and 25 were hydrodeiodinated to the methylene derivatives 17, 18, and 27, respectively. Complete minally connected to the 5-enopyranose 1, and the 5-enofuranoses 8 and 23 by addition, in the presence of sodium di-deprotection of the perfluoroalkyl-substituted pyranose 3 (prepared from 1), and of the furanoses 17 and 18 led to the thionite, of the corresponding homologous perfluoroalkyl iodides to the double bond. Up to six products were separated carbohydrate-based amphiphilic mesogens 29/30, 21, and 22, respectively, with a perfluoroalkyl tail. These formed me-from each reaction mixture and then fully characterised. The 5-iodo derivatives 9, 10 (prepared from 8), 24, 25, and 26 sophases of the smectic A type. (prepared from 23) were diastereomeric mixtures (5R/5S).