Chemoselective cross metathesis of bishomoallylic alcohols: rapid access to fragment a of the cryptophycins.
[reaction: see text] The racemic or enantioselective allylation of in situ formed beta,gamma-unsaturated aldehydes provides efficient access to bishomoallylic alcohols from readily available 2-vinyloxiranes. These products, when subjected to modified Grubbs cross metathesis conditions, afforded terminally homologated products in moderate to good yields with high E selectivity and without degradation of the enantiomeric excess. The compounds obtained through this two-step sequence yield fragments of an important and pharmacologically active family of cryptophycins.
Lautens
Mark
M
Davenport Research Laboratories, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada. mlautens@alchemy.chem.utoronto.ca
Maddess
Matthew L
ML
D000438:Alcohols / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D047630:Depsipeptides; D005027:Ethylene Oxide / Q000031:analogs & derivatives / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D010456:Peptides, Cyclic / Q000138:chemical synthesis*; D012428:Ruthenium / Q000737:chemistry; D013237:Stereoisomerism; D013997:Time Factors
D000438:Alcohols; D047630:Depsipeptides; D009942:Organometallic Compounds; D010456:Peptides, Cyclic; C088419:cryptophycin; D012428:Ruthenium; D005027:Ethylene Oxide