title: Anti-selective aldol reactions with titanium enolates of N-glycolyloxazolidinethiones.
abstract: [reaction: see text] A highly diastereoselective anti aldol addition utilizing a variety of N-glycolyloxazolidinethiones has been developed. Enolization of an N-glycolyloxazolidinethione with titanium (IV) chloride and (-)-sparteine followed by addition of an aldehyde activated with additional TiCl(4) resulted in highly anti-selective aldol additions, typically with no observable syn isomers. Allyl-protected glycolates demonstrated the highest levels of selection and yields, although O-benzyl and O-methyl glycolyloxazolidinethiones also performed well.
authors.affiliation: Venable and Kenan Laboratories of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. crimmins@email.unc.edu
authors.forename: Michael T
authors.initials: MT
authors.lastname: Crimmins
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: McDougall
mesh_terms: D000438:Alcohols / Q000737:chemistry; D006016:Glycolates / Q000737:chemistry; D013237:Stereoisomerism; D013871:Thiones / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D000438:Alcohols; D006016:Glycolates; D013871:Thiones; C025096:titanium tetrachloride; D014025:Titanium