Preparation of Optically Enriched Secondary Alkyllithium and Alkylcopper Reagents—Synthesis of (−)‐Lardolure and Siphonarienal |
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| Authors: | Varvara Morozova Juri Skotnitzki Dr Kohei Moriya Prof?Dr Konstantin Karaghiosoff Prof?Dr Paul Knochel |
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| Affiliation: | Department Chemie, Ludwig-Maximilians-Universit?t München, München, Germany |
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| Abstract: | Optically enriched secondary alkyl iodides were converted into secondary alkyllithium and secondary alkylcopper compounds with very high retention of configuration. Quenching with various electrophiles, including chiral epoxides, provided a range of chiral molecules with high enantiomeric purity (>90 % ee). This method has been applied in an iterative fashion in the total synthesis of (?)‐lardolure in 13 steps and 5.4 % overall yield (>99 % ee, dr>99:1) and siphonarienal in 15 steps and 5.6 % overall yield (>99 % ee, dr>99:1) starting from commercially available ethyl (R)‐3‐hydroxybutyrate (>99 % ee). |
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| Keywords: | asymmetric synthesis copper iterative synthesis lithium pheromone synthesis |
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