Strategies and Tactics In Organic Synthesis

Contributors

Preface


1. Theme and Variations: A Synthesis of Superphane

I. Introduction, Goals, and Synthetic Philosophy

II. Theme

III. Variations

IV. A Synthesis of Superphane

V. Further Variations

References


2. The Total Synthesis of Gibberellic Acid

I. Introduction

II. The Synthetic Challenge

III. The Synthetic Strategy

IV. Preliminary Studies: Stereocontrolled Elaboration of the A Ring

V. Model Studies: The Intramolecular Diels-Alder Strategy is Tested

VI. Model Studies: A Method for the Construction of the C and D Rings

VII. The Hydrindane Approach

VIII. The Hydronaphthalene Approach: (1) The Advance to Chandra's Dione

IX. The Hydronaphthalene Approach: (2) Operations on the C Ring

X. The Hydronaphthalene Approach: (3) The D Ring

XI. The Hydronaphthalene Approach: (4) Subjugation of the Β Ring

XII. The Hydronaphthalene Approach: (5) The Triumph of the Intramolecular Diels-Alder Strategy

XIII. The Hydronaphthalene Approach: (6) Stalemate at the A Ring

XIV. The Total Synthesis of Gibberellic Acid

References


3. A Prostaglandin Synthesis

I. Introduction

II. 7-Oxaprostaglandins

III. Prostaglandin F2α

IV. 13,14-Dehydroprostaglandins

References


4. Synthesis of Indole Alkaloids

I. Introduction

II. Early Thoughts

III. Initial Results: First Phase

IV. Flexible Strategy-Flexible Tactics: Second Phase

V. Synthesis of (±)-Aspidospermidine: Third Phase

VI. Reverse Roles: Fourth Phase

VII. Completion of the "Model Work"

VIII. New Territory

References


5. Synthesis of Tylonolide, the Aglycone of Tylosin

I. Introduction

II. General Strategy

III. Preliminary Work

IV. Synthesis

V. Concluding Remarks

References


6. Pericyclic Reactions in Organic Synthesis and Biosynthesis: Synthetic Adventures with Endiandric Acids A-G

I. Introduction: The Appealing Endiandric Acid Cascade

II. Retrosynthetic Analyis of Endiandric Acids A-G

III. Synthesis of the Key Bicyclic Intermediate

IV. Functionalization of the Bicyclic Intermediate: Synthesis of Endiandric Acids D, E, F, and G

V. The Intramolecular Diels-Alder Reactions: Synthesis of Endiandric Acids A, B, and C

VI. Conclusions

References


7. Plato's Solid in a Retort: the Dodecahedrane Story

I. Introduction

II. The Decision against Convergency and Building of the Cornerstone

III. A Retrosynthetic Glimpse and Symmetry Considerations

IV. Arrival at the "Closed" and "Open" Dilactones

V. Chemical Reactivity of the "Open" Dilactone

VI. Functionalization Reactions of the "Closed" Dilactone

VII. (C2)-Dioxa-C20-Octaquinane, a Heterocyclic Trisecododecahedrane

VIII. The Pilot Photochemical Experiment

IX. Trisecododecahedranes via Dichloro Diester Reduction

X. The Monoseco Level of Elaboration

XI. Installation of the Final Bond: Formation of 1,16-Dimethyldodecahedrane

XII. Further Developments

XIII. Controlled Monosubstitution and Isolation of an Isododecahedrane

XIV. Bypassing the Unwanted Reaction Pathway

XV. (CH)20: The Parent Dodecahedrane

References


8. The Synthesis of Fomannosin and Illudol

I. Introduction

II. The Target

III. The Ketene Cycloaddition Approach to Fomannosin

IV. Synthesis of Illudol and Fomannosin from a Common Intermediate

V. Summary

References


9. Evolution of a Synthetic Strategy: Total Synthesis of Jatrophone

I. Introduction

II. General Background

III. A Strategy for the Total Synthesis of Jatrophone

IV. Synthesis of Simple 3(2H)-Furanones: The First Major Spin-Off of the Jatrophone Program

V. A Successful Conclusion to Phase I: Synthesis of 3(2H)-Furanone 21

VI. Synthesis of α-Hydroxymethylcyclopentenone: An Initial Solution

VII. An Alternate Approach to α-Hydroxymethylcyclopentenone: Development of a Versatile Latent α-Ketovinyl Anion Equivalent

VIII. Synthesis of the Pentenomycins, Their Epimers, and Dehydropentenomycin: A Major Diversion

IX. Return to the Jatrophone Problem: A Successful Failure

X. Development of An Alternative 3(2H)-Furanone Protocol: A New 1,3-Diketone Synthesis

XL Exploitation of the Improved 3(2H)-Furanone Protocol

XII. Macrocyclization: A Difficult Step

XIII. Completion of Phase II: Synthesis of Normethyljatrophone

XIV. Phase III: The Stereochemical Problem

XV. Total Synthesis of Jatrophone and Its Epimer: The Final Goal

XVI. Further Diversions during the Jatrophone Synthetic Program

XVII. Reactions of Simple 3(2H)-Furanones and Furadienones with Propanethiol

XVIII. Jatrophone Analogs: cis- and trans-Normethyljatropholactones

XIX. Isolation of Three New Jatrophone Derivatives

XX. Interplay of Structure and Conformation of the Jatrophone Nucleus vis-a-vis Antitumor Activity

References


10. On the Stereochemistry of Nucleophilic Additions to Tetrahydropyridinium Salts: A Powerful Heuristic Principle for the Stereorationale Design of Alkaloid Syntheses

Text

References


11. A Nonbiomimetic Approach to the Total Synthesis of Steroids: the Transition Metalcatalyzed Cyclization of Alkenes and Alkynes

I. Introduction

II. Model Studies in Cobalt-Mediated Alkyne Cyclizations

III. Cobalt-Mediated [2 + 2 + 2]Cycloadditions en Route to Annulated Cyclohexadienes

References


12. Evolution of a Strategy for Total Synthesis of Streptonigrin

I. Introduction

II. Synthetic Strategy

III. Preliminary AB-Ring Studies

IV. Preliminary CD-Ring Studies

V. Synthesis of Streptonigrin

References


13. Methynolide and the Prelog-Djerassi Lactonic Acid: an Exercise in Stereocontrolled Synthesis

I. Introduction

II. Excursions from 2,4-Dimethylfuran

III. Further Expeditions from 8-Oxabicyclo[3.2.1]octanes

IV. The Prelog-Djerassi Lactonic Acid (4)

V. A Cycloheptanoid Route to Methynolide

References

Index