Pseudo-guaianolide

From six-membered rings Rearrangement as part of the pseudo-guaianolide to confertin synthesis [14]. 

Cycloheptane derivatives (7, 192-193). Wender et a/. have applied their cycloheptane annelation procedure to total syntheses of the pseudoguaianolides damsinic acid (1) and confertin (2). The paper describes the synthesis of 1-lithio-l-methyl-2-vinylcyclopropane, which is the annelation reagent utilized in the pseudo-guaianolide syntheses. 

The continued search for novel synthetic routes to the sesquiterpene pseudo-guaianolides has resulted in several new approaches to the hydroazulene ring system. Lansbury and Serelis have shown that the hydroxycyclopentanone (191) undergoes facile cationic cyclization on treatment with formic acid, leading directly to the hydroazulenedione (192). Further manipulation of (192) led to the total synthesis of damsinic acid (193). In an impressive synthesis of the closely... 

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