Naturalproductman’s Blog

Hey, is that a natural product?!

Archive for the ‘Alkaloids’ Category

Power of enzymes

Posted by naturalproductman on March 30, 2014

Kenji Watanabe and co-workers at Shizuoka University have reported in Chembiochem on the formation of dimeric diketopiperazine alkaloids from a cytochrome P450.

 

Chembiochem paper

Posted in Alkaloids, Cascade Reactions, Dimer, Methodology, Radical Chemistry | Leave a Comment »

Fumigatoside A

Posted by naturalproductman on March 17, 2014

Someone has brought to my attention the isolation of a recent alkaloid containing a strange alkynol attached to a nitrogen.

The main supporting evidence for this structure is the 3-bond HMBC correlation of the OH proton to the alkyne carbon taken in DMSO (the alcohol is at ~9.8 ppm).  The fishy thing here is that there is no 2-bond HMBC correlation (I assume it would be two bond from O-H and C-O) from the OH to the nearest alkyne carbon.

An interesting question would be how this alkynol would be introduced in the biological system. Alkynes are usually precursors to alkynols in P450 reactions and give rise to a rearrangement to form ketenes, which inactivate the enzymes.

Synthetically, I first saw alkynol structures from Sergey Kozmin’s work back in 2006. I should say that even here they are not alkynols – they are siloxy alkynes.

Perhaps anybody else has an opinion on this interesting structure?
alkynol

OL paper

Posted in Alkaloids, Biosynthesis | Leave a Comment »

Lyconadins A and C syntheses

Posted by naturalproductman on March 10, 2014

Mingji Dai and co-workers from Purdue have reported in ACIE on the syntheses of lyconadins A and C.

lyconadins A and C

ACIE paper

Posted in Alkaloids, Asymmetric, Cascade Reactions, Methodology, Total Synthesis | Leave a Comment »

Benzyne chemistry for tubingensin A

Posted by naturalproductman on February 19, 2014

Neil Garg and co-workers have reported in JACS on the synthesis of tubingensin A. An interesting [2+2] reaction occurred between a benzyne and an enolate.

2+2

JACS paper

Posted in Alkaloids, benzyne, Cascade Reactions, Methodology | Leave a Comment »

Sculponeatin N synthesis

Posted by naturalproductman on February 19, 2014

Regan Thomson and co-workers from Northwestern have reported on the synthesis of sculponeatin N.

alkaloid

ACIE paper

Posted in Alkaloids, Methodology, Total Synthesis | Leave a Comment »

Aspidophylline A synthesis

Posted by naturalproductman on February 2, 2014

Dawei Ma and co-workers have reported in ACIE on the synthesis of aspidophylline A.

aspidophylline A

ACIE paper

Posted in Alkaloids, Methodology, Total Synthesis | Leave a Comment »

Lundurine synthesis

Posted by naturalproductman on January 17, 2014

Atsushi Nishida and co-workers from Chiba University have reported in Org Lett on the synthesis of lundurine.

lundurine

OL paper

Posted in Alkaloids, Cascade Reactions, Methodology, Total Synthesis | Leave a Comment »

Indole alkaloids

Posted by naturalproductman on December 17, 2013

Jieping Zhu and co-workers haver reported in JACS on the syntheses of some indole alkaloids.

indole

 

 

JACS paper

Posted in Alkaloids, Indoles, Methodology, Total Synthesis | Leave a Comment »

Neofinaconitine synthesis

Posted by naturalproductman on December 13, 2013

David Y.-K. Chen and colleague have reported in ACIE on the synthesis of

alkaloid

ACIE paper

Posted in Alkaloids, Total Synthesis | Leave a Comment »

Posted by naturalproductman on December 13, 2013

Noritaka Chida and co-workers from Keio University have reported in ACIE on the synthesis of gephyrotoxin.

gephyrotoxin
ACIE paper

Posted in Alkaloids, Total Synthesis | Leave a Comment »

 
Follow

Get every new post delivered to your Inbox.

Join 66 other followers