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Since the isolation of unique tricyclic diterpenoid vinigrol , its promising biological activities and complex framework have resulted in numerous synthetic efforts to the total synthesis of this venerable molecule for the past two and half decades. This mini review highlights the significance of various synthetic strategies towards this structurally unique and challenging natural product. [ABSTRACT FROM AUTHOR]

Isoryanodane diterpenoids possess a densely oxygenated and intricately fused pentacycle (ABCDE-ring), although its unique ring system has not yet been assembled chemically. The 6/5/7-membered BCD-rings of isoryanodanes differ from the 5/6/6-membered rings of the structurally-related ryanodanes. We previously achieved the total synthesis of ryanodine and five other ryanodane diterpenoids by employing the common ABDE-tetracyclic intermediate 1 . Herein, we report a new strategy for constructing isoryanodane ABCDE-ring structure 3 from 1 via a combination of the oxy-Cope rearrangement and SmI 2 -mediated transannular cyclization. [ABSTRACT FROM AUTHOR]

The stereoselective syntheses of the tricyclic core structure of vinigrol and highly functionalized polycyclic molecules from 5-bromo-2-methoxyphenol in five synthetic steps are reported. Intramolecular and intermolecular Diels–Alder reactions and tandem oxy-Cope/ene reactions are the key steps in the synthesis. [ABSTRACT FROM AUTHOR]

An efficient one-pot synthesis of a 10,10-ethylenebicyclo[5.2.1]dec-8-en-4-one derivative, which can be considered as a synthetic intermediate for the taxane skeleton, has been achieved by tandem anionic [1,3] and oxy-Cope rearrangements of 2-vinylbicyclo[3.2.1] oct-6-en-2-ol. [Copyright &y& Elsevier]

Abstract: Oxidative coupling reaction of both 3-hydroxychrysene and 2-hydroxybenzo[c]phenanthrene by using Cu(NO3)2–3H2O under atmospheric air is described. The former gave the aimed coupled biaryl derivative. However, the latter gave a further oxidized helical quinone derivative. The unique helical structure was characterized by X-ray and NMR analysis. [Copyright &y& Elsevier]