Naturalproductman’s Blog

Hey, is that a natural product?!

Archive for the ‘Diterpenoids’ Category

Looks like Guanacastepene

Posted by naturalproductman on July 20, 2010

Yoshihiro Sato and co-workers from Hokkaido University have published in Synthesis on a rhodium catalyzed method to access a 5,7,6-tricyclic substrate from an monocyclic polyolefin precursor.

rhodium

Synthesis paper

Posted in Cascade Reactions, Diterpenoids, Methodology, Rhodium, Transition Metal | Leave a Comment »

Heptemerone G Synthesis

Posted by naturalproductman on July 20, 2010

Jerzy Wicha and co-workers at the Polish Academy of Sciences have published in Tetrahedron Letters on the synthesis of heptemerone G.  They started from the 5,7-bicyclic portion and formed the 6 membered ring via an Aldol condensation.

heptemerone G

TL paper

Posted in Aldol, Diterpenoids, Methodology, Named Reactions, Seven-Membered Rings, Total Synthesis | Leave a Comment »

Isolushinins A−J

Posted by naturalproductman on June 3, 2010

Han-Dong Sun and co-workers at the Kunming Institute of Botany have published in the Journal of Natural Products on the isolation of some new diterpenoids with cytotoxic activity.  Isolushinin A had an IC50 value of 1.1 micromolar against HL-60 cell lines.

kaurene

JNP paper

Posted in Diterpenoids | Leave a Comment »

Pierisoids A and B

Posted by naturalproductman on April 21, 2010

Sheng-Hong Li and co-workers from the Chinese Academy of Sciences have recently reported in Organic Letters on the isolation of some diterpenoids:  pierisoids A and B, which had antifeedant effects against the cotton bollworm with antifeedant index of54.9% at 5.54 nanograms/cm2 and 40.7% at 5.67 nanograms/cm2 for pierisoids A and B, respectively.

pierisoids


OL paper

40.7% at 5.67 × 10−3 μg/cm2

Posted in Diterpenoids, Seven-Membered Rings | Leave a Comment »

Dollabelane

Posted by naturalproductman on April 12, 2010

Abimael Rodriguez and co-workers from the University of Puerto Rico have recently published in the Journal of Natural Products on some dolabellane structures isolated from some gorgonian octocorals found in the Caribbean Sea.  These diterpenes had 9.5-59.6 micromolar IC50 values against Plasmodium falciparum.

eunicea

    JNP paper

Posted in Diterpenoids | Leave a Comment »

Secorhodomollolides

Posted by naturalproductman on March 11, 2010

Jiangong Shi and co-workers from the Institute of Materia Medica have recently published in Organic Letters on the isolation of secorhodomollolides.  Secorhodomollolide B had an IC50 value of 0.97 micromolar against hepatoma Bel-7402 cell lines.

selective

OL paper

Posted in Diterpenoids, Seven-Membered Rings | Leave a Comment »

Trichocarpinine

Posted by naturalproductman on February 1, 2010

Sometimes natural products occur as dimers of two separate natural products.  Trichocarpinine is one such dimer – a hetidine/hetisine type bisditerpenoid alkaloid.  Feng-Peng Wang and co-workers at Sichuan University have recently reported its isolation in Helvetica Chimica Acta.

trichocarpinine
HCA paper

Posted in Alkaloids, Dimer, Diterpenoids | Leave a Comment »

Salvileucalin B via Cyclopropanation

Posted by naturalproductman on January 20, 2010

Sarah Reissman and co-workers at Caltech have recently published an interesting approach towards the polycyclic core of salvileucalin B.  At first glance, because the starting material was a alpha-diazoketone compound, I was thinking that it’s going to be a carbene C-H insertion reaction to form one C-C bond.  However, the reaction was a cyclopropanation.

cyclopropanation
OL paper

Isolation of Salvileucalin B from OL

Posted in Carbene, Cascade Reactions, Copper, Diterpenoids, Methodology, Ring forming, Transition Metal | Leave a Comment »

Cubitane Synthesis

Posted by naturalproductman on January 19, 2010

Thomas Lindel and co-workers at TU Braunschweig have recently published in Organic Letters on the enantioselective synthesis of a cubitane carbon skeleton that is a 12-membered macrocycle.  The method they used was the radical cyclization approach.  There is a carbon carbon bond cleavage involved that requires the introduction of an alpha-hydroperoxy group on a ketone followed by an alkyl shift, which leads to the generation of an oxacarbenium ion that gets hydrolyzed to yield the 12-membered macrocycle.  The alpha-hydroperoxy ketone intermediate is generated by treating the ketone with lithium aluminum hydride in ether for 2 days under air exposure.

cubitane
OL paper

Posted in C-C Bond Breaking, Cascade Reactions, Cubitane, Diterpenoids, Methodology, Peroxides, Radical Chemistry, Ring Opening | Leave a Comment »

Asymmetric Heck Coupling

Posted by naturalproductman on December 8, 2009

Manabu Node and co-workers at Kyoto Pharmaceutical University have recently published in JOC on the synthesis of (-)-dichroanal B, (-)-dichroanone, and taiwaniaquinone H via an asymmetric Heck coupling using R-synphos as the chiral ligand.

asymmetric Heck

JOC paper

Posted in Asymmetric, Cascade Reactions, cross coupling, Diterpenoids, Methodology, Transition Metal | Leave a Comment »