Stereospecific entry to [4.5]spiroketal glycosides using alkylidenecarbene C-H insertion.
[reaction: see text] A novel method for the stereospecific preparation of [4.5]spiroketal glycosides utilizing the 1,5 C-H bond insertion of alkylidenecarbenes is described. Treatment of 2-oxopropyl beta-pyranosides A with lithium (trimethylsilyl)diazomethane in THF at -78 degrees C afforded 1,6-dioxaspiro[4,5]decenes B in good yield. Submission of the corresponding alpha-glycosides C to the same reagent gave the isomeric insertion products D in moderate to high yield.
Wardrop
Duncan J
DJ
Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA. wardropd@uic.edu
Zhang
Wenming
W
Fritz
Joseph
J
D003978:Diazomethane / Q000031:analogs & derivatives / Q000737:chemistry*; D006027:Glycosides / Q000737:chemistry*; D007202:Indicators and Reagents; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D013141:Spiro Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
C451480:(trimethylsilyl)diazaomethane; D006027:Glycosides; D007202:Indicators and Reagents; D013141:Spiro Compounds; D014297:Trimethylsilyl Compounds; D003978:Diazomethane