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Articles tagged with: Diels-Alder

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[14 Jan 2012 | 33 Comments | 24,536 views]
Fusarisetin A

Li, Deng, Zhu, Lu, Yu. JACS, 2011, ASAP. DOI: 10.1038/nchem.1196  
Just take a quick look at that target and consider that the synthetic route I’m about to summarise took thirteen steps.  I’m fairly stunned – I read the top-line number in the abstract, and immediately thought that they must have started with an advanced intermediate or degredation product, but no – the synthetic action (like many natural product syntheses) begins with Citronellal.  Sure, only three of the rings are carbocyclic, but there’s a lot going on here, so lets get into …

Featured, Still In The RBF »

[7 Dec 2011 | 23 Comments | 22,867 views]
Taxane Skeleton

Baran, Mendoza, Ishihara. Nature Chem., 2011, EarlyView. DOI: 10.1038/nchem.1196   
Hmm… I’m still not convinced about whether I should really post on this paper, but I’m interested in it, so to hell with the rules!  What we’ve got here is a sort-of meta-synthesis; Baran doesn’t actually make any of the taxane natural products, but demonstrates an extremely neat synthesis of a potential common precursor.  The theory behind the work is related to previous Baran diatribes, where he points out that too many steps in syntheses simply oxidise and reduce the same …

Still In The RBF »

[15 Sep 2010 | 29 Comments | 24,691 views]
Caribenol A

Li, Yang, Liu,Han, Yue. JACS, 2010, AOP. DOI: 10.1021/ja106585n
It’s weird how diseases that seemed to belong to Charles Dickens can come back to haunt the modern world – except this time armed against our battery of treatments.  One such beastie is TB, which is something that’s becoming increasingly prevalent in the UK, about 60 years after it had been banished to historical literature.  Coupled with the fact that many other nations have just had to deal with it, and we’ve got a new grant-winning target – something Caribenol A has …

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[18 Aug 2010 | 17 Comments | 22,841 views]
Manzamine A

Fukuyama, Toma, Kita. JACS, 2010, ASAP. DOI: 10.1021/ja103721s
Ah – now this is a bit of a blast-from-the-past.  I knew I’d written something about this molecule before, so I had a quick rummage in the Tot. Syn. folder on my PC – and found nothing.  So I had a look in the other Tot. Syn folder, and another place I keep stuff for this website, and then four or five other places… (yeah, great filing system here) …and it turned up in this presentation I wrote a life-time ago.  You can …

Still In The RBF »

[18 Jan 2010 | 16 Comments | 16,893 views]

Shibasaki, Kanai, Shimizu, Shi, Usuda. ACIEE, 2010, EarlyView. DOI: 10.1002/anie.200906678. ; Shibasaki, Kanai, Kuramochi, Usuda. Org. Lett., 2004, 6, 4387. DOI: 10.1021/ol048018s. 
Three amazingly tough targets completed in (almost) as many months – you can’t tell me that total synthesis is stifled.  Hyperforin has been staining the white-boards of many a lab for decades – the isolation (reported in Antibiotik…) was way back in ’71, and has resisted synthesis until now.  Shibasaki himself has been working on it for quite a while, as you’ll have seen in the header – a key …

Still In The RBF »

[31 Oct 2009 | 105 Comments | 52,977 views]

Baran, Maimone, Shi, Ashida. JACS, 2009, ASAP. DOI: 10.1021/ja908194b.
Yep, it’s done.  Surprised?  You shouldn’t be, not after the Angewandte published last year, which was tantalisingly close to the natural product.  For the uninitiated, this target has been on grant-proposals world-wide for the last twenty years, subsequent to it’s isolation in 1987, culminating in nearly twenty ‘syntheses towards’ type papers, but no cigar until now.  And don’t think that those incomplete approaches were by the Bionic Bros – were talking big names like Paquette.  So what did Baran do to triumph? …

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[11 Oct 2009 | 36 Comments | 16,422 views]
Aigialomycin D

Barrett, Calo, Richardson. Org. Lett., 2009, ASAP. DOI: 10.1021/ol901979x.
Macrolactones?  From Barrett?  It’s not his usual fayre, but as is more normal, there is a twist in the synthesis.  I think most chemists (or at least me…), when presented with a target like aigialomycin, would think about buying-in the aromatic portion, and then trying to bolt on the styrene-type olefin and building around.  However, with his interests in reactive intermediates, Tony Barrett (of IC, London… just down the road), it comes of no real surprise to me that he …

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[15 Sep 2009 | 23 Comments | 16,199 views]
Hirsutellone B

Nicolaou, Sarlah, Wu, Zhan. ACIEE, 2009, ASAP. DOI: 10.1002/anie.200903382.
Yep, I took my sweet time about blogging this.  Hell, it’s been over a week since my last post… no excuses, I’ve been living on Spotify, and trying to justify buying a Canon 7D.  So not reading much chemistry then, but I did see this (actually, it was my former labmate, Phil, who linked-me-up).  A damn nice piece of work, with an interesting mix of old and new chemistry.  The target was found in a fungus, but was …

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[28 Jun 2009 | 63 Comments | 42,317 views]

Movassaghi, Tjandra, Qi. JACS, 2009, ASAP. DOI: 10.1021/ja903790y.
Okay, I missed my ‘I’ll blog it by Saturday‘ deadline by a day, but it’s taken quite some time to get my head round these structures.  And beer.  However, I think I’ve got there – so ladies and gents – on with one of the best syntheses this year.
First up scheme-wise is a rather nice Suzuki coupling.  Taking a standard boronic acid, mixing in a vinyl-gem-dibromide, they achieved a selective E,E- product in cracking yield.  However, this came at …

Methods, Still In The RBF »

[25 Feb 2009 | 14 Comments | 15,433 views]

Nicolaou, Lim, Becker. ACIEE, 2009, EarlyView. DOI: 10.1002/anie.200900058.
Huh; you wait months for a Nicolaou synthesis, and then two come at once!  This little beastie and sporolide B dropped in Angewandte on consecutive days, both represented by abstracts drawn in the now familiar crayon-o-vision styling of La Jolla’s most-prolific chemist and photoshop abuser. Seriously, check this stuff out – this is on his home page!  The last time I saw anything like this I’d been over-doing both the ether and the geocities…

Of course, all this wouldn’t be …