Intramolecular 1,3-dipolar additions in 4-O-allyl pyranoside 6-nitrones: An approach to chiral pyrano-pyrans and pyrano-oxepans

✍ Scribed by P.M. Collins; M.S. Ashwood; H. Eder; S.H.B. Wright; D.J. Kennedy

• Publisher: Elsevier Science
• Year: 1990
• Tongue: French
• Weight: 201 KB
• Volume: 31
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)88914-5

✦ Synopsis

Treametu qf rhe easily prepared 6-aldehydo-BlucopyrMosidc allyl ether (5) with N-benzylh~o@mine gave drone (a), which underwet~ a 13-dipolar oddiiion IO the 4-O-&l group giving &er deprorection and hydrogenolysis the chiral pyrano-pyran (11) and tk pyrano-oxepan (13).

Pyranwpyrans and pyrano-oxepans are important targets for chemical synthesis because they am constituenta of the madne toxin brevetoxin B'. Particularly significant in this area of chemical synthesis is the wok Of Nicolaou* and ~then?~~ who have produced derivatives of the fused O-hetemcycles which may be readily adapted for further fusion of mom ether rings.