3-(1-Ethylamino-ethylidene)-1-methyl-pyrrolidine-2,4-dione

3-(1-Ethylamino-ethylidene)-1-methyl-pyrrolidine-2,4-dione was obtained as an unexpected product in a three-step synthesis starting with o-nitrobenzoyl sarcosine, acetoacetanilide and ethylamine. The compound showed moderate antibacterial activity against S. aureus and E. coli.

Total Synthesis of Cladosins B and C

A convergent synthetic route to the fungal metabolites cladosins B and C has been developed, affording these natural products in 29% and 27% overall yield, respectively. The cladosins are rare examples of hybrid polyketides featuring a 3-enamine tetramic acid group derived from l-valine. Key steps in this modular six-step sequence include a DMAP-mediated O- to C-acyl rearrangement to unite the side chains with the tetramic acid core and subsequent amine incorporation using either ammonium acetate or HMDS.

Asymmetric total synthesis of filamentous fungi related resorcylic acid lactones 7-epi-zeaenol and zeaenol

An efficient, short and, a convenient asymmetric total synthesis of filamentous fungi related resorcylic acid lactones 7-epi-zeaenol (2) and zeaenol (1) have been achieved in 7 and 9 linear steps with the high overall yield of 32% and 21% respectively, from the known intermediate 13. Mitsunobu inversion, De Brabander’s protocol for macrolactonisation, Heck cross-coupling, diastereoselective alkyne aldehyde coupling and Ohira–Bestmann alkynylation are the key reactions.

Marine natural products

Covering: January to December 2017This review covers the literature published in 2017 for marine natural products (MNPs), with 740 citations (723 for the period January to December 2017) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1490 in 477 papers for 2017), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. Geographic distributions of MNPs at a phylogenetic level are reported.