title: Anti and syn glycolate aldol reactions with a readily displaced thiol auxiliary.
abstract: The TBDPS protected glycolate derivative of thiol auxiliary 1 is readily prepared (3 steps, 80% overall yield) and has been shown to give excellent anti:syn selectivity (>97:3) and high facial selectivity (88:12 to 97:3) in glycolate aldol reactions with a range of aldehydes (75-87% isolated yield major diastereomer). In contrast, its benzyl protected counterpart displays more versatility with respect to the generation of either anti or syn glycolate aldol adducts, but only modest facial selectivity. The thiol auxiliary has been shown to be readily displaced under mild conditions to give alcohol and ester derivatives of the glycolate aldol adducts.
authors.affiliation: School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, United Kingdom.
authors.forename: Sandra
authors.initials: S
authors.lastname: Fanjul
authors.forename: Alison N
authors.initials: AN
authors.lastname: Hulme
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis; D000447:Aldehydes / Q000737:chemistry*; D001547:Benzaldehydes / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004952:Esters / Q000138:chemical synthesis; D006016:Glycolates / Q000737:chemistry*; D007202:Indicators and Reagents; D021241:Spectrometry, Mass, Electrospray Ionization; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D000438:Alcohols; D000447:Aldehydes; D001547:Benzaldehydes; D004952:Esters; D006016:Glycolates; D007202:Indicators and Reagents; D013438:Sulfhydryl Compounds; C032175:benzaldehyde