Asymmetric synthesis of the (4aS,8aR,8S)-hydrolilolidone system. A formal total synthesis of unnatural (+)-aspidospermine

1989 ◽  
Vol 54 (19) ◽  
pp. 4673-4676 ◽  
Author(s):  
A. I. Meyers ◽  
Daniel Berney
Keyword(s):  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
System A

General Cyclopropane Assembly via Enantioselective Redox-Active Carbene Transfer to Aliphatic Olefins

2018 ◽  
Author(s):  
Marc Montesinos-Magraner ◽  
Matteo Costantini ◽  
Rodrigo Ramirez-Contreras ◽  
Michael E. Muratore ◽  
Magnus J. Johansson ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Chemical Space ◽  
Synthetic Approach ◽  
Asymmetric Cyclopropanation ◽  
Redox Active ◽  
Wide Range ◽  
Leaving Group ◽  
Stereoelectronic Properties ◽  
Carbene Transfer

Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates and reagents, even when targeting similar compounds. This limits the speed and chemical space available for discovery campaigns. Here we introduce a practical and versatile diazocompound, and we demonstrate its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. We found that the redox-active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect enabled the asymmetric cyclopropanation of a wide range of olefins including unactivated aliphatic alkenes, enabling the 3-step total synthesis of (–)-dictyopterene A. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally-differentiated diazocompounds are viable and advantageous equivalents of single-carbon chirons<i>.</i>

scholarly journals Heronapyrrole D: A case of co-inspiration of natural product biosynthesis, total synthesis and biodiscovery

2014 ◽  
Vol 10 ◽  
pp. 1228-1232 ◽  
Author(s):  
Jens Schmidt ◽  
Zeinab Khalil ◽  
Robert J Capon ◽  
Christian B W Stark
Keyword(s):  
Antibacterial Activity ◽  
Natural Products ◽  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Natural Product ◽  
Joint Effort ◽  
Natural Product Biosynthesis ◽  
New Members ◽  
Degree Of Oxidation ◽  
Rare Class

The heronapyrroles A–C have first been isolated from a marine-derived Streptomyces sp. (CMB-0423) in 2010. Structurally, these natural products feature an unusual nitropyrrole system to which a partially oxidized farnesyl chain is attached. The varying degree of oxidation of the sesquiterpenyl subunit in heronapyrroles A–C provoked the hypothesis that there might exist other hitherto unidentified metabolites. On biosynthetic grounds a mono-tetrahydrofuran-diol named heronapyrrole D appeared a possible candidate. We here describe a short asymmetric synthesis of heronapyrrole D, its detection in cultivations of CMB-0423 and finally the evaluation of its antibacterial activity. We thus demonstrate that biosynthetic considerations and the joint effort of synthetic and natural product chemists can result in the identification of new members of a rare class of natural products.

scholarly journals Asymmetric Synthesis of Quinine: A Landmark in Organic Synthesis

2006 ◽  
Vol 1 (10) ◽  
pp. 1934578X0600101 ◽  
Author(s):  
Vijay Nair ◽  
Rajeev S. Menon ◽  
Sreekumar Vellalath
Keyword(s):  
Organic Chemistry ◽  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Organic Synthesis ◽  
Chemical Industry ◽  
Crucial Role ◽  
Historical Perspective ◽  
Modern Medicine ◽  
Present Review ◽  
Catalytic Asymmetric Synthesis

Ever since its isolation in 1820, Quinine has played a crucial role in the development of organic chemistry, the chemical industry and modern medicine. A total synthesis of quinine, widely regarded as an event of epochal importance, was claimed by Woodward and Doering in 1945. This work, however, heavily relied on unsubstantiated literature reports and it appears that Woodward's work fell short of a total synthesis of quinine. The first total synthesis of quinine was reported by Uskokovic in the 1970s. The first stereoselective total synthesis of quinine was accomplished only in 2001, by Stork, who incidentally is the originator of the concept of stereoselectivity in total synthesis. Apart from the stereoselectivity, Stork's synthesis of quinine is remarkable for its conceptual uniqueness and retrosynthetic novelty. Naturally, this work has been attested as a landmark in organic synthesis by leaders in the field. Subsequently, Jacobson and Kobayashi reported the catalytic asymmetric synthesis of quinine in 2003 and 2004, respectively. Both these synthesis have followed a similar approach. The present review has attempted to provide a concise account of the synthesis of quinine from a historical perspective.

Studies toward the Total Synthesis of Sorangicins: Asymmetric Synthesis of the Key Fragments

Synlett ◽  
2004 ◽  
Vol 2004 (15) ◽  
pp. 2689-2692 ◽  
Author(s):  
Dieter Schinzer ◽  
Claudia Schulz ◽  
Olga Krug
Keyword(s):  
Total Synthesis ◽  
Asymmetric Synthesis

Studies Towards the Total Synthesis of Epothilones: Asymmetric Synthesis of the Key Fragments

1996 ◽  
Vol 2 (11) ◽  
pp. 1477-1482 ◽  
Author(s):  
Dieter Schinzer ◽  
Anja Limberg ◽  
Oliver M. Böhm
Keyword(s):  
Total Synthesis ◽  
Asymmetric Synthesis
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