Identification and Synthesis of Mycalol Analogues with Improved Potency against Anaplastic Thyroid Carcinoma Cell Lines.

The marine metabolite mycalol (1) has a specific inhibitory activity on cells of anaplastic thyroid carcinoma (ATC), a very aggressive and rare cancer that does not have effective conventional therapy. In this study, we describe six new related analogues (2-7) that differ in the length of the terminal alkyl residue and the presence of acetate or 3S-hydroxybutyrate (3S)-3HB as a substituent at C-19. Despite the structural analogies, some of the new members were significantly more cytotoxic than 1 on cell lines derived from human ATC.

Determination of the Absolute Configuration of Gliomasolide D through Total Syntheses of the C-17 Epimers.

The absolute configuration at C-17, the carbon bearing the distal hydroxy group of the 14-membered natural product gliomasolide D, was assigned as R by comparison of C NMR shifts and specific rotation values of the epimers at C-17. The first total synthesis of gliomasolide D along with its C-17 epimer, regioselective macrocyclization (18 membered vs 14 membered), and regioselective Wacker oxidation are highlights of the present work.

First Total Synthesis of Gliomasolide C and Formal Total Synthesis of Sch-725674.

Syntheses of two 14-membered macrolides Sch-725674 and Gliomasolide C are described here. The first total synthesis of Gliomasolide C, the short synthesis of Sch-725674, and regioselective Wacker oxidation of internal olefin are the highlights of this disclosure. In addition, a key macrocycle with orthogonal functionalities was designed and synthesized on a gram scale for the generation of analogues.

Design, Synthesis, and Identification of Silicon Incorporated Oxazolidinone Antibiotics with Improved Brain Exposure.

Therapeutic options for brain infections caused by pathogens with a reduced sensitivity to drugs are limited. Recent reports on the potential use of linezolid in treating brain infections prompted us to design novel compounds around this scaffold. Herein, we describe the design and synthesis of various oxazolidinone antibiotics with the incorporation of silicon.

Total synthesis and structural revision of mycalol, an anticancer natural product from the marine source.

The total synthesis of an anticancer (anaplastic thyroid) natural lipid mycalol has been accomplished for the first time. Synthesis of originally proposed structure necessitated the revision of structure in which the position of acetate group moved from C20 to C19 and a change in stereochemistry of the glycerol unit.

Ready access to functionally embellished cis-hydrindanes and cis-decalins: protecting group-free total syntheses of (±)-Nootkatone and (±)-Noreremophilane.

A simple and efficient synthesis of functionalized cis-hydrindanes and cis-decalins was achieved using a sequential Diels-Alder/aldol approach in a highly diastereoselective manner. The scope of this method was tested with a variety of substrates and was successfully applied to the synthesis of two natural products in racemic form. The highlights of the present work provide ready access to 13 new cis-hydrindanes/cis-decalins, a protecting group-free total synthesis of an insect repellent Nootkatone, and the first synthesis of a Noreremophilane using the shortest sequence.

Synthesis of palmyrolide A and its cis-isomer and mechanistic insight into trans-cis isomerisation of the enamide macrocycle.

Concise and protecting-group free synthesis of ent-palmyrolide A and (-)-cis-palmyrolide A were achieved starting from commercially available (S)-citronellal. The key fragment of palmyrolide A, "(5S,7S)-7-hydroxy-5,8,8-trimethylnonanamide", which makes up the most challenging part of the target molecule, was prepared in just three steps. A plausible mechanism for the trans-cis isomerization of the double bond in the macrocycle has been investigated.