Protocols for the preparation of each of the four possible stereoisomeric. alpha.-alkyl-. beta.-hydroxy carboxylic acids from a single chiral aldol reagent

NA Van Draanen, S Arseniyadis…

Index: Draanen, Nanine A. Van; Arseniyadis, Simeon; Crimmins, Michael T.; Heathcock, Clayton H. Journal of Organic Chemistry, 1991 , vol. 56, # 7 p. 2499 - 2506

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Citation Number: 131

Abstract

Protocols have been devised whereby all four possible stereoisomeric a-alkyl-@-hydroxy carboxylic acids can be derived from a single aldol reagent, hydroxy ketone 3. Compound 3, obtained in enantiomerically homogeneous form in 50% overall yield from tert-butylglycine (l), is used for aldol reactions in the form of ita trimethylsilyl and tert-butyldimethylsilyl derivatives, 4 and 5. The 2 lithium and 2 boron enolates of 4 react with various aldehydes ...