10.1016/S0957-4166(00)00327-X
The study focuses on the stereocontrolled cyclopropanation of enones derived from (S)-Garner’s aldehyde, aiming to synthesize 1,2,3-trisubstituted cyclopropanes with potential biological activities. The researchers utilized sulfonium ylides, specifically ethyl (dimethylsulfuranylidene)acetate (EDSA), generated in situ from ethyl dimethylsulfonium acetate bromide and DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), to react with enones 5 derived from (S)-Garner’s aldehyde in toluene. The major isomer produced from this reaction was found to have the configuration 2R,1’S,2’S,3’S. The study also explored the synthesis of a 3-benzyl analogue of the CCG family compounds, which are known for their biological significance. Various enones, sulfonium ylides, and reaction conditions were investigated to assess the scope and diversity of the reaction, ultimately concluding that the reaction allows for the assembly of 1,2,3-trisubstituted cyclopropanes with great diversity, potentially leading to the synthesis of biologically important compounds such as CCG analogues.
10.1055/s-2004-835663
The study presents a novel methodology for synthesizing N-diphenylmethylene-2-vinyl-substituted cyclopropylamines, which are significant in pharmaceuticals and natural products due to their biological activity. The synthesis begins with allylsulfones, specifically compound 11, which can be obtained in both enantiomeric forms. The researchers utilized various chemicals, including base treatments for allylsulfones to form trans:cis cyclopropanols, and molecular modeling to study the stereoselectivity of cyclopropane formation. The study also involved the use of Garner’s aldehyde, a key intermediate in synthesizing biologically active compounds, and the transformation of amino alcohols into cyclopropylamines with the help of protecting groups like Tosyl, Boc, Moc, and benzyl. The purpose of these chemicals was to achieve high diastereoselectivity in the synthesis of chiral amino-cyclopropanes, which are valuable as building blocks for the synthesis of conformationally restricted amino acids. The study's innovative approach and findings contribute to the field of asymmetric synthesis, particularly for cyclopropylamines.
10.1021/jo1005284
Yuji Yoshimitsu et al. present a concise and stereoselective synthesis of four diastereomers of pachastrissamine, a cytotoxic natural product isolated from marine sponges. The authors utilized Garner’s aldehyde as the sole chiral source to construct all three stereogenic centers of the diastereomers. Their strategy involved converting Garner’s aldehyde into a common intermediate, diol 6a, which was then used to synthesize the natural pachastrissamine through bis-tosylation and cyclization. The 2-epi-pachastrissamine was obtained via monotosylation and spontaneous cyclization of a D-ribophytosphingosine derivative. The 3-epi- and 2,3-epi-pachastrissamines were synthesized using a regio- and stereospecific ring-opening reaction of an orthoester assisted by a Boc group. This approach allowed for the divergent synthesis of all four diastereomers from a single intermediate, highlighting the efficiency and versatility of their synthetic method.
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