Covering July 2013 The natural product sesquiterpenyl indoles are structural hybrids from farnesyl pyrophosphate and tryptophan or its precursors, often with unusual and complex structural features, many of them with interesting biological activities. In this review the compounds of this class known until now are classified, a biosynthetic approach of each group is proposed and a review of the synthesis or synthetic approaches is communicated.

A highly convergent total synthesis of the anthelmintic macrolide avermectin B1a 1 is described. The key features of this synthesis include the introduction of the C(11)–C(15) portion by selective ring opening of a symmetrical 1,4-bis-epoxide 4 followed by reaction with the anion derived from the 3-methyl-2-(1-methylpropyl)-6-phenylsulphonylpyran 3 to afford the ‘northern’ C(11)–C(25) fragment 39. Coupling of the derived C(11)–C(25) aldehyde unit 42 with a C(1)–C(10)‘southern’ fragment 2 was achieved via a novel deconjugative vinyl sulphone anion sequence. Macrolactonisation and subsequent introduction of the 3,4-double bond gave the aglycone portion 51. The oleandrosyloleandrose disaccharide was introduced by a novel silver-mediated coupling between the 5-acetylated aglycone 70 and the thiocarbonylimidazolide 69. Final deacetylation was accomplished using Super-Hydride to give the natural product 1.

This paper focuses on the latest developments in asymmetric epoxidation of electron-deficient olefins since the review by Porter and Skidmore on chiral ligand-metal peroxide systems, polyamino acid catalysed and organocatalysed epoxidations. Particular attention has been paid to the most recent advances using chiral pyrrolidines as organocatalysts.

The quinone/hydroquinone sesquiterpenes of drimane or rearranged drimane skeletons constitute a wide and diverse group of secondary metabolites of mixed biogenesis. These compounds are mainly of marine origin and their interest is not only for the variety of isolated structure but for the interesting biological activities that they present. In this paper a series of quinone/hydroquinone sesquiterpenes of natural origin that have been reported to date is presented. The structures of these compounds are gathered into eight groups with reference to their biological activities and compounds synthesised.