Experimental evidence for chair-like transition states in aldol reactions of methyl ketone lithium enolates: stereoselective synthesis and utilization of a deuterium-labeled enolate as a probe of reaction stereochemistry.
Aldol reactions of methyl ketone lithium enolates proceed via chairlike Zimmerman-Traxler transition states with 7:1 to 50:1 preference over alternative, boatlike transition structures, as determined by studies involving the configurationally stable deuterium-labeled enol silane 18 as the lithium enolate precursor.
Liu
Christopher M
CM
Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA.
Smith
William J
WJ
Gustin
Darin J
DJ
Roush
William R
WR
D000438:Alcohols / Q000138:chemical synthesis*; D000447:Aldehydes / Q000737:chemistry*; D003903:Deuterium; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry; D010422:Pentanones / Q000737:chemistry*; D013237:Stereoisomerism
D000438:Alcohols; D000447:Aldehydes; D007659:Ketones; D009942:Organometallic Compounds; D010422:Pentanones; D008094:Lithium; D003903:Deuterium