Enantioselective Synthesis of a Novel Trans Double Bond Ceramide Analogue via Catalytic Asymmetric Dihydroxylation of an Enyne. The Role of the Trans Double Bond of Ceramide in the Fusion of Semliki Forest Virus with Target Membranes

The oxyanion derived from hydroxyacrylate E-(5) undergoes smooth intramolecular Michael addition to give the trans-2,6-disubstituted tetrahydropyran (7) as the major product of reaction. In contrast, the oxyanion obtained from isomer Z-(5) cyclizes to give the cis-2,6-disubstituted tetrahydropyran (6) as the major product. Such chemistry has been extended to the enantioselective synthesis of (+)-(6) the acquisition of which constitutes a formal total synthesis of acid (+)-(2), a constituent of the glandular secretion from the civet cat (Viverra civetta). Reductive amination of keto acrylate (12) affords an intermediate amine which cyclizes, in situ, to give the cis-2,6-disubstituted piperidine (26). Analogous treatment of compound (13) delivers the isomeric trans-2,6-disubstituted piperidine (27) as the exclusive product of reaction. Transition state structures have been proposed to account for the diastereoselectivities observed in all of the cyclization reactions.

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Enantioselective synthesis of 20(S)-camptothecin using sharpless catalytic asymmetric dihydroxylation

Tetrahedron Asymmetry ◽

10.1016/0957-4166(95)00154-h ◽

1995 ◽

Vol 6 (6) ◽

pp. 1245-1248 ◽

Cited By ~ 43

Author(s):

Sang-sup Jew ◽

Kwang-dae Ok ◽

Hee-jin Kim ◽

Myoung Goo Kim ◽

Jong Min Kim ◽

...

Keyword(s):

Enantioselective Synthesis ◽

Asymmetric Dihydroxylation ◽

Catalytic Asymmetric

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Total Synthesis of Camptothecins: An Update

Synlett ◽

10.1055/s-0036-1588738 ◽

2017 ◽

Vol 28 (10) ◽

pp. 1134-1150 ◽

Cited By ~ 7

Author(s):

Fen-Er Chen ◽

Lei Chen

Keyword(s):

Total Synthesis ◽

Stereoselective Synthesis ◽

Enantioselective Synthesis ◽

The Novel ◽

Asymmetric Dihydroxylation ◽

New Methods ◽

Considerable Research ◽

Catalytic Asymmetric ◽

Synthetic Approaches ◽

Asymmetric Hydroxylation

Over the last few decades, considerable research efforts have been directed toward the development of effective chemical syntheses of camptothecin and its analogs. The last comprehensive review of this area was published in 2003 and many effective new methods have since been reported for the stereoselective synthesis of the camptothecin alkaloids. In this account, we have summarized most of the novel synthetic approaches developed for the synthesis of camptothecins during the last decade. We have focused on strategies for the construction of the pentacyclic ring system and the different methods used to install the chiral quaternary center on the E ring of camptothecin.1 Introduction2 Synthesis of Racemic Camptothecins3 Enantioselective Synthesis of Camptothecins3.1 Sharpless Asymmetric Dihydroxylation3.2 Catalytic Asymmetric Cyanosilylation3.3 Auxiliary-Induced Asymmetric Carbonyl Addition3.4 Catalytic Asymmetric Ethylation3.5 Asymmetric Hydroxylation4 Conclusion

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