Alkali metal counterion control of enolate protonation stereoselectivity.
[reaction: see text] Generation of the lithium salt of the norbornenol shown (M = H) followed by quenching with aqueous NH(4)Cl solution gives predominantly the beta-epimeric ketone 6. Similar production of the potassium alkoxide leads instead to the alpha-epimer (99:1). These results reveal the potential importance of alkali metal counterions as stereocontrol elements.
Hu
Yang
Y
Evans Chemical Laboratories, The Ohio State University, Columbus, 43210, USA.
Bishop
Raynauld L
RL
Luxenburger
Andreas
A
Dong
Shuzhi
S
Paquette
Leo A
LA
D000643:Ammonium Chloride / Q000737:chemistry; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D008094:Lithium / Q000737:chemistry; D008672:Metals, Alkali / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D011522:Protons; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry
D007659:Ketones; D008672:Metals, Alkali; D009942:Organometallic Compounds; D011522:Protons; D000643:Ammonium Chloride; D014867:Water; D008094:Lithium