Approach towards an EPC synthesis of nodusmicin — III. Preparation of the oxygen bridged decalin part of nodusmicin

Gössinger, Edda; Graupe, Michael; Kratky, Christoph; Zimmermann, Kurt

doi:10.1016/s0040-4020(97)00065-3

Cited by 14 publications

(3 citation statements)

References 59 publications

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“…meso -1,4-Diol 23 has been used as the starting material for the synthesis of a macrolide antibiotic nodusmicin and its analogue 18-deoxynargenicin . In the synthesis, it has been reported that attempts to generate the chiral monoacetate by esterification of 23 or hydrolysis of the diacetate of 23 with several enzymes failed .…”

Section: Resultsmentioning

confidence: 99%

Asymmetric Acylation of sec-Alcohols with Twisted Amides Possessing Axial Chirality Induced by the Adjacent Asymmetric Center

and

Katsumata

1999

J. Org. Chem.

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This paper reports that axially chiral twisted amides serve as asymmetric acylating agents for sec-alcohols under neutral conditions. Kinetic resolution of various racemic sec-alcohols and desymmetrization of 1,2-, 1,3-, and 1,4-meso-diols were performed by using the twisted amides. The utility of this desymmetrization method was shown by the preparation of the synthetic intermediate 28 for macrolide antibiotic nodusmicin and 18-deoxynargenicin. The stereoselectivity of the acylation reactions is significantly dependent on the bulkiness of both the acyl group and the C-4 substituent of the chiral auxiliary. When an amide possessing an imidazolyl group at C-4 was employed, the stereoselectivity was reversed to give R esters. A possible working model of the acylation reaction is also described on the basis of the structural studies of the twisted amides by IR and 1 H and 13 C NMR spectroscopies and AM1 calculations. These studies suggested that rotamer II is thermodynamically more stable than the others. The rotamer II has an axial chirality about its C(O)-N linkage that is induced by the adjacent chiral center. This would enable discrimination of the two enantiomeric hydroxy groups of the racemic alcohols or meso-diols.

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Section: Resultsmentioning

confidence: 99%

Asymmetric Acylation of sec-Alcohols with Twisted Amides Possessing Axial Chirality Induced by the Adjacent Asymmetric Center

and

Katsumata

1999

J. Org. Chem.

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“…[5] To date no general techniques have been revealed which could be used to build up the required structural motive independently of other substituents in a stereocontrolled manner. Encouraged by the successful application of metallated 2-alkenyl sulfoximines in the diastereoselective synthesis of highly substituted THF derivatives [6] we started to consider more robust solutions to the synthetic problem outlined above.…”

Section: Introductionmentioning

confidence: 99%

Metallated 2-Alkenyl Sulfoximines in Asymmetric Synthesis: Regio- and Stereoselective Synthesis of Highly Substituted Oxabicyclic Ethers and Studies Towards the Total Syntheses of the Euglobals G1 and G2 and Arenaran A

1999

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2‐Cyclopentenyl‐ and 2‐cyclohexenylmethyl sulfoximines can be converted into angular carbon‐functionalised, highly substituted, isomerically pure (ds ≥ 98%) 2‐oxabicyclo[3.3.0]octanes and 2‐oxabicyclo[3.4.0]nonanes in high yields by a convenient one‐pot sequence. Molecular frameworks such as these can be found in many biologically active natural products. In addition to the methodological work, we report on studies towards the total synthesis of the euglobals G1 and G2 and arenaran A.

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“…[3aR-(3aa,4b,7a,7aa)]-N,N-Dimethyl-(octahydro-8, 8-dimethyl-2-oxo-4,7-methano-benzofuran-7-yl)-methanesulfonamide (9 [3aR-(3aa,4b,7a,7aa)]-N,N-Diethyl-(octahydro-8,8-dimethyl-2-oxo-4,7-methano-benzofuran-7-yl)-methanesulfonamide (10 …”

Section: General Procedures For the Preparation Of Sulfonamidesmentioning

confidence: 99%

Increasing chiral recognition in acetal formation

et al. 2008

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Approach towards an EPC synthesis of nodusmicin — III. Preparation of the oxygen bridged decalin part of nodusmicin

Cited by 14 publications

References 59 publications

Asymmetric Acylation of sec-Alcohols with Twisted Amides Possessing Axial Chirality Induced by the Adjacent Asymmetric Center

Asymmetric Acylation of sec-Alcohols with Twisted Amides Possessing Axial Chirality Induced by the Adjacent Asymmetric Center

Metallated 2-Alkenyl Sulfoximines in Asymmetric Synthesis: Regio- and Stereoselective Synthesis of Highly Substituted Oxabicyclic Ethers and Studies Towards the Total Syntheses of the Euglobals G1 and G2 and Arenaran A

Increasing chiral recognition in acetal formation

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