Evolution of the Total Syntheses of Batzellasides the First Marine Piperidine Iminosugar

Batzellasides A-C are C-alkylated piperidine iminosugars isolated from a sponge Batzella sp. The first total synthesis of (+)-batzellaside B was achieved by employing a chiral pool approach starting from L-arabinose for the construction of a piperidine ring system. Subsequently a practical second-generation synthesis was developed by utilizing a Sharpless asymmetric dihydroxylation for the preparation of the common piperidine intermediate elaborated in the first-generation synthesis. The overall yield of batzellaside B was improved to 3.3% by introducing the exocyclic C8 stereocenter via facial selective hydride addition to a linear ketone. These syntheses allowed for the determination of the absolute stereochemistry of this natural product as well as for providing precious samples which would pave the way for further biological studies.

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Determination of the Absolute Stereochemistry and Asymmetric Total Synthesis of Madindolines A (I) and B (II): A Practical Improvement to a Second-Generation Approach from the First-Generation.

ChemInform ◽

10.1002/chin.200542228 ◽

2005 ◽

Vol 36 (42) ◽

Author(s):

Tomoyasu Hirose ◽

Toshiaki Sunazuka ◽

Daisuke Yamamoto ◽

Naoto Kojima ◽

Tatsuya Shirahata ◽

...

Keyword(s):

Total Synthesis ◽

First Generation ◽

Second Generation ◽

Asymmetric Total Synthesis ◽

The Absolute ◽

Absolute Stereochemistry

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Determination of the absolute stereochemistry and asymmetric total synthesis of madindolines A and B: a practical improvement to a second-generation approach from the first-generation

Tetrahedron ◽

10.1016/j.tet.2005.04.056 ◽

2005 ◽

Vol 61 (25) ◽

pp. 6015-6039 ◽

Cited By ~ 31

Author(s):

Tomoyasu Hirose ◽

Toshiaki Sunazuka ◽

Daisuke Yamamoto ◽

Naoto Kojima ◽

Tatsuya Shirahata ◽

...

Keyword(s):

Total Synthesis ◽

First Generation ◽

Second Generation ◽

Asymmetric Total Synthesis ◽

The Absolute ◽

Absolute Stereochemistry

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Stereoselective total syntheses of (±)-sinularene and (±)-5-epi-sinularene: a general intramolecular Diels–Alder approach to tricyclic sesquiterpenes

Canadian Journal of Chemistry ◽

10.1139/v85-166 ◽

1985 ◽

Vol 63 (4) ◽

pp. 993-995 ◽

Cited By ~ 8

Author(s):

Kazimierz Antczak ◽

John F. Kingston ◽

Alex G. Fallis

Keyword(s):

Double Bond ◽

Methyl Ester ◽

Total Synthesis ◽

Ring System ◽

Diels Alder ◽

Exocyclic Double Bond ◽

Total Syntheses ◽

Methyl Group ◽

Secondary Hydroxyl ◽

Selective Hydrogenolysis

Stereoselective total synthesis of (±)-sinularene and (±)-5-epi-sinularene are described. The sequence employs a "blocked" cyclopentadiene in which the cyclopropane unit also serves as a latent methyl group. Thus intramolecular [4 + 2] cycloaddition of the substituted methyl spiro[2.4]hepta-4,6-dien-1-yl)-2-pentenoate 11 affords 5-benzyloxy-6-isopropyl-8-carbomethoxytetracyclo[5.4.01,7.02,4.02,9]undec-10-ene (12) which after selective hydrogenolysis generates the tricyclo[4.4.01,6.02,8]decane (sinularene) ring system. Removal of the secondary hydroxyl function (Ph3P/CCl4/CH3CN; H2/Pd/C), reduction of the methyl ester (LiAlH4), and introduction of the exocyclic double bond (acetate pyrolysis, 550 °C) completes the synthesis of (±)-sinularene in 14 steps from cyclopentadiene. A parallel series of reactions employing the isopropyl epimer of 12 affords (±)-5-epi-sinularene.

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ChemInform Abstract: Total Synthesis of Brevetoxin A. Part 1. First Generation Strategy and Construction of BCD Ring System.

ChemInform ◽

10.1002/chin.199923287 ◽

2010 ◽

Vol 30 (23) ◽

pp. no-no

Author(s):

K. C. Nicolaou ◽

Mark E. Bunnage ◽

Daniel G. McGarry ◽

Shuhao Shi ◽

Patricia K. Somers ◽

...

Keyword(s):

Total Synthesis ◽

First Generation ◽

Ring System ◽

Brevetoxin A

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A radical mediated first total synthesis from ‘diacetone glucose’ and determination of the absolute stereochemistry of xylobovide

Tetrahedron Letters ◽

10.1016/j.tetlet.2004.12.123 ◽

2005 ◽

Vol 46 (8) ◽

pp. 1307-1309 ◽

Cited By ~ 11

Author(s):

G.V.M. Sharma ◽

T. Gopinath

Keyword(s):

Total Synthesis ◽

The Absolute ◽

Absolute Stereochemistry

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Synthetic study of ravidomycin, a hybrid natural product

Pure and Applied Chemistry ◽

10.1351/pac200072091783 ◽

2000 ◽

Vol 72 (9) ◽

pp. 1783-1786 ◽

Cited By ~ 9

Author(s):

Keisuke Suzuki

Keyword(s):

Natural Products ◽

Total Synthesis ◽

Natural Product ◽

Amino Sugar ◽

Antitumor Antibiotics ◽

Ready Availability ◽

Silyl Acetals ◽

Gilvocarcin V ◽

Absolute Stereochemistry

Strategies and tactics associated with the total synthesis of hybrid natural products are discussed. The target is ravidomycin (2), one of the gilvocarcin-class antitumor antibiotics with an aryl C-glycoside structure. The first total synthesis of 2, which was achieved along similar lines of that of gilvocarcin V (1), served for the determination of the relative as well as the absolute stereochemistry of 2. Also revealed was a limitation of the synthetic scheme so long as the amino sugar congener was concerned. A preliminary result is discussed on the [2+2+2] approach that relies on the ready availability of various benzocyclobutene derivatives via regioselective [2+2] cycloaddition of α-alkoxybenzynes and ketene silyl acetals.

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