Highly diastereoselective lithium enolate aldol reactions of butane-2,3-diacetal desymmetrized glycolic acid and deprotection to enantiopure anti-2,3-dihydroxy esters.
[reaction--see text] The butane-2,3-diacetal (BDA) desymmetrized glycolic acid building block 1 undergoes efficient and highly diastereoselective lithium enolate aldol reactions with both aromatic and aliphatic aldehydes to afford, after an acidic methanolysis deprotection step, the enantiopure anti-2,3-dihydroxy esters in good yield.
Dixon
D J
DJ
Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
Ley
S V
SV
Polara
A
A
Sheppard
T
T
D000080:Acetals; D000478:Alkylation; D002384:Catalysis; D004952:Esters; D007202:Indicators and Reagents; D008094:Lithium; D018020:Lithium Compounds; D012821:Silanes; D013237:Stereoisomerism
D000080:Acetals; D004952:Esters; D007202:Indicators and Reagents; D018020:Lithium Compounds; D012821:Silanes; C442342:butane-2,3-diacetal glycolic acid; D008094:Lithium; C442341:lithium hexamethyldisilazide