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STRATEGIES FOR THE SYNTHESIS OF LYSERGIC ACID. (+)-Lysergic acid [(+)-1] is a precursor of several substances with well-established pharmacological properties, including some drugs approved and commercialized around the world. Thus, the importance of (+)-1 as a synthetic target becomes undoubted and various strategies for the synthesis of its tetracyclic core have been reported in the literature. Therefore, in this review article we will address in chronological order the total and formal syntheses of lysergic acid (1), separating them into racemic and chiral/asymmetric syntheses. Until now, there are 24 syntheses described in the literature, namely, 11 total and 13 formal syntheses. Considering all the syntheses accomplished, 15 were planned to produce (±)-lysergic acid [(±)-1] and 9 presented routes to eventually provide (+)-lysergic acid [(+)-1]. A significant evolution regarding approaches and efficiency may be observed since the first synthesis of (±)-1 until the last asymmetric synthesis of (+)-1.

In this paper we gathered articles concerning insertion reactions of arynes, exclusively generated from 2-(trimethylsilyl)aryl triflates in the presence of fluoride ions, in substrates bearing nucleophilic and electrophilic portions separated by sigma bonds. Accordingly, we stand out the great importance and versatility of such transformations in the preparation of highly functionalized aromatic systems, which are hardly synthesized in just one step for other methods.