Highly stereoselective aldol reactions of titanium enolates from lactate-derived chiral ketones.
[reaction: see text] Highly stereoselective titanium-mediated aldol reactions based on lactate-derived ketones are reported. The stereochemical outcome of the process depends on the protecting group (PMB or Bn) and the Lewis acid (i-PrOTiCl(3) or TiCl(4)) used in the enolization step, the corresponding anti-syn or syn-syn aldols being prepared in high yields and with diastereomeric ratios up to 99:1.
Solsona
Joan G
JG
Departament de Química Orgànica, Universitat de Barcelona, Martí i Franqués 1-11, 08028 Barcelona, Catalonia, Spain.
Romea
Pedro
P
Urpí
Fèlix
F
Vilarrasa
Jaume
J
D000447:Aldehydes / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry; D007773:Lactates / Q000737:chemistry; D013237:Stereoisomerism; D014025:Titanium / Q000737:chemistry*
D000447:Aldehydes; D007659:Ketones; D007773:Lactates; D014025:Titanium