Synthesis of 1,2-cis-Configurated Glycosylphosphonates

✍ Scribed by Roger Meuwly; Andrea Vasella

• Book ID: 102858155
• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: German
• Weight: 713 KB
• Volume: 69
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19860690105

✦ Synopsis

2 (92%), 3 (5%) 4 (93^/0), 5 (5%) 8 (899;8), 9 (6%) 10 (90%), 11 (5%) 14 (88%), 15 (6%) 16 (90%), 17 (5%) 20 (86%), 21 (9%) 22 (84%), 23 (9%) Surprisingly, under analogous conditions, the CI -u-mannopyranose 7') also yielded the 1,2-cis-configurated dimethyl and diethyl phosphonates 8 (89%) and 10 (90%), respectively, as the major and the 1,2-trans-configurated anomers 9 (6%) and 11 (5%) as the minor products. A very similar behaviour was observed in the case of the furanoses 13 [ l l ] and 19 [12] giving mainly the 1,2-cis-configurated phosphonates 14, 16, 20, and 22 respectively. In each case, the 1,2-trans-isomers 15, 17, 21, and 23 were isolated as the minor products [Table I). The 1,2-cis-configurdted diethyl phosphonates 10, 16, and 22 were deprotected as indicated above to give the @'-D-mannopyrdnosyl)phosphonate 12 (96 Yo), the (a -D-ribofuranosy1)phosphonate 18 (98 YO) and the @'-u-arabinofurano-sy1)phosphonate 24 (97 YO), respectively.

The assignment of the configuration at the anomeric center of the glycosylphosphonates w d S based on their spectroscopic properties.