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Articles Archive for March 2007

Still In The RBF »

[29 Mar 2007 | 6 Comments | 3,967 views]

I think it’s quite probably time to de-stress a bit, so we’ve got a fantastic second set of named reaction problems created by our game-show-style host, Simon. This batch are considerably more difficult than the last, so I’ll be impressed if anyone can get a correct set of answers in two hours like last time… (busy today, Dr. Porter?). You can find them here.
The first correct set are in… and the winners are “Davey Stoker and the rest of the Pattenden Monkeys at Nottingham” (direct quote…)! Well done folks… …

Still In The RBF »

[27 Mar 2007 | 43 Comments | 6,216 views]

Baran, Maimone and Richter. Nature, 2007, 446, 404-408. DOI: 10.1038/nature05569.
There’s actually not too much more to add to this synthesis of three further related natural products – using chemistry familiar from the previous synthesis, they were able to complete 11-epi-fischerindole G in only six steps from carvone oxide. With this target already complete, a simple oxidation with DDQ returned fischerindole I in one step and in a great yield.

However, using xenon difluoride for fluorohydroxylation of the indole was certainly less simple; the disconnection to electrophile addition, addition of water, rearrangement …

Still In The RBF »

[25 Mar 2007 | 24 Comments | 5,368 views]

Can you believe it? Yep, tot.syn.com is now a whole year old! In some ways, I can’t believe I’ve only been doing this for one year; in others, it’s kinda scary people are still reading this! It seems I joined the blogosphere just as things were kicking-off; the true pioneers (Derek, Dylan, Paul Bracher and Mitch) had been at it for a while – and I stumbled upon Tenderbutton through a completely random search. Then crazy thoughts happened, and I gave it a go… (I’ve certainly got a bit more …

Still In The RBF »

[25 Mar 2007 | Comments Off | 1,979 views]

There were a lot of options for this period, and a few more I accidentally missed out… damn… but the results are conclusive:
Amphidimolide E: 5% (8)
Vigulariol: 6% (10)
Rapamycin: 9% (14)
Dictyostatin: 1% (2)
Oasomycin: 9% (15)
Tashironin: 21% (34)
Phorboxazole B: 7% (11)
Merrilactone: 11% (17)
Fusicoauritone: 2% (4)
Intricatetraol: 2% (3)
Hedychilactone B: 2% (4)
Phalarine: 14% (22)
Pleocarpenone: 11% (17)
Total Votes : 161
So congrats to the Danishefsky group – I’m sure this stands as one of his greatest accolades…

Still In The RBF »

[24 Mar 2007 | 14 Comments | 6,521 views]

Baran, Maimone and Richter. Nature, 2007, 446, 404-408. DOI: 10.1038/nature05569.
If you read this blog, and you haven’t hassled me about a post on this paper, you’re actually in the minority. It’s from what appears to be a bit of a special on chemistry – or at least I’m not used to seeing quite this much in Nature. In the commentary, we’ve got a highlight by John Porco on this paper, a piece on C-H activation, and a review by F. Dean Toste on relativistic effects in gold catalysis. And as …

Still In The RBF »

[21 Mar 2007 | 16 Comments | 6,352 views]

Trost, Cramer, and Bernsmann. JACS, 2007, 129, 3086-3087. DOI: 10.1021/ja070142u.
Another article I’ve managed to bypass over the last few months, and what a stunner it is too. Marcfortine B certainly has a diverse structure, with a particularly intimidating bicyclo[2.2.2]diazaoctane core; perhaps more usefully, the family it belongs to also has potent anthelmintic activity. With the focus on the spirocyclic cyclopentanone moiety, Trost envisaged that their own TMM (trimethylenemethane) chemistry might produce that complex functionality with ease:

They get to that juicy part of the chemistry rather quickly, with the starting material …

Still In The RBF »

[20 Mar 2007 | 9 Comments | 6,430 views]

Evans and Adams. JACS, 2007, 129, 1048-1049. DOI: 10.1021/ja0684996.
I somehow missed this brilliant synthesis by Evan, published online in January, though in my defense, I was moving town and University :). Anyway, it’s a fantastic piece of work on a molecule we’ve seen at Tot. Syn. Towers a few months back, published by Samuel Chackalamannil at the Schering-Plough Research Institute. As mentioned in the paper, the bark from which this target was isolated has been used by native tribes of Papua New Guinea as a medical treatment, and related compounds …

Still In The RBF »

[16 Mar 2007 | 7 Comments | 3,163 views]

Sorry, folks – this is seriously belated! I’ve combined a December and January into one poll, as I’m sure well all took some time off at new year, but that’s not to belittle the syntheses. It’s a tough call – but your one!
PS. For the uninitiated, the poll is over there —–>

Still In The RBF »

[15 Mar 2007 | One Comment | 4,751 views]

Rychnovsky and La Cruz. JOC, 2006, ASAP. DOI: 10.1021/jo0626459
You gotta love full-papers, and this synthesis by Scott Rychnovsky (a favourite author here at Tot.Syn. Towers…) benefits greatly from the space for explanation. They could easily have contracted the publication to a letter or communication, but so much would have been lost. Anyway, on with the science; the target – Attenol A – contains that most annoying of features, a non-anomerically stabilised spiroketal. Damn. So making that ring system was going to need a special touch, and Rychnovsky decided to apply …

Still In The RBF »

[14 Mar 2007 | 6 Comments | 4,984 views]

Folks, I don’t know how your week is going, but mine has been quite stressful so far, so I was deeply impressed when my esteemed collegue, Simon Sprague, presented a little set of named reaction problems. With a difference. Y’see, all you need to do is connect a series of pictures with a named reaction, much in the “bee” + “leaf” = “believe” manner. I’ve linked to the problem set here, as a pdf.

The comments are now open, and the answers are posted as comment one.

PS. It’s a bit anglo-centric, …