New oxidative tools for the functionalization of the cephalostatin north 1 hemisphere.

Abstract

Dimethyldioxirane (DMDO) C-H oxidation of ketone 17 to hemiketal 18 (82%), bis-dehydration to vinyl ether 21 (77%), and DMDO again provides C-23 axial alcohol 23 (99%). Routine processing, including a double-stereoselective Sharpless AD reaction (de >98%), gives alcohols 7 and 32. C-23 deoxy substrate 7 undergoes Suarez hypoiodite oxidative cyclization to (natural) beta spiroketal 34, but compound 32, bearing a C-23 silyl ether, generates unnatural spiroketal 33. [reaction: see text]

• Authors: Jong Seok Lee, Philip L Fuchs
• Journal: Organic letters (Org Lett) Vol. 5 Issue 13 Pg. 2247-50 (Jun 26 2003) ISSN: 1523-7060 [Print] United States
• PMID: 12816420 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Epoxy Compounds
• Ethers, Cyclic
• Phenazines
• Spiro Compounds
• dimethyldioxirane

Topics

• Cyclization
• Epoxy Compounds (chemistry)
• Ethers, Cyclic (chemistry)
• Oxidation-Reduction
• Phenazines (chemistry)
• Spiro Compounds (chemistry)
• Stereoisomerism