159000-41-6Relevant articles and documents
Controlling π-Facial Diastereoselectivity in the 1,3-Dipolar Cycloadditions of Diazomethane to Chiral Pentenoates and Furanones: Enantioselective Stereodivergent Syntheses of Cyclopropane Hydroxy Acids and Didehydro Amino Acids
Martin-Vila, Marta,Hanafi, Neuh,Jimenez, Jose M.,Alvarez-Larena, Angel,Piniella, Joan F.,Branchadell, Vicenc,Oliva, Antonio,Ortuno, Rosa M.
, p. 3581 - 3589 (2007/10/03)
The title compounds have been synthesized in both enantiomeric forms and in good overall yields by using D-glyceraldehyde as the single chiral precursor. The efficiency and usefulness of the synthetic routes have been secured by performing controlled manipulations of the functional groups and by highly stereoselective transformations, namely Wittig-Horner condensations and cyclopropanations. Cyclopropane derivatives have been synthesized through 1,3-dipolar cycloaddition of diazomethane to chiral pentenoates or furanones obtained, in turn, from D-glyceraldehyde. Syn/ anti stereochemistry of the cycloadducts has been unequivocally assigned and rationalized. Since π-facial diastereoselectivity involved in these cycloadditions is the opposite for cyclic and open- chain structures, enantiomeric series of products can be derived.
Effective uses of dirhodium(II) tetrakis[methyl 2-oxopyrrolidine-5(R or S)-carboxylate] for highly enantioselective intermolecular cyclopropenation reactions
Doyle, Michael P.,Protopopova, Marina,Müller, Paul,Ene, Doina,Shapiro, Evgeny A.
, p. 8492 - 8498 (2007/10/02)
The title compounds are effective catalysts for intermolecular cyclopropenation reactions of 1-alkynes with diazo esters and diazo amides. Diastereoselectivities achieved from the appropriate match with d- or l-menthyl diazoacetate are 77 to ≥ 94% de. Ena
