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Articles tagged with: alkaloid

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[20 Aug 2011 | 28 Comments | 12,735 views]
Axinellamines Pt. II

Baran, Su, Rodriguez. J. Am. Chem. Soc, 2011, ASAP. DOI: 10.1021/ja206191g
When does a person or groups work in a particular area of total synthesis become pedestrian, or even dull? This may sound harsh (especially as he’s a really nice guy), but Paterson’s (at Cambridge) work on macrolides isn’t doing it for me any more. Conversely, Baran’s work in the area of pyrrole-imidazole alkaloids is still facinating, even though I’ve blogged about it more than a few times! What we’re looking at here, though, isn’t …

Guest Post, Still In The RBF »

[29 Jul 2011 | 10 Comments | 14,978 views]
Trigonoliimines A-C

Guest Blogger: See-Arr-Oh
Han and Movassaghi, JACS 2011, 10768-10771. DOI: 10.1021/ja204597k ; Qi, Bao, and Tambar, JACS 2011, 10050-10053. DOI: 10.1021/ja203960b .
It’s not too often JACS publishes total syntheses anymore, since their role as a general chemistry journal means every newly built molecule competes against quantum dots, in silico simulations,  or new battery materials. So you can imagine my utter shock and delight at finding not one, but two almost back-to-back syntheses in the past month!  First, the Porco / Ready combination of Kibdelone C, followed closely by two syntheses …

Still In The RBF »

[11 Jun 2011 | 7 Comments | 10,711 views]
Aspidophylline A

Garg, Zu, Boal. JACS, 2011, ASAP. DOI: 10.1021/ja203227q
So – when one ‘old-schools-up’ a synthesis, is that a homage, or just ho-hum?  I guess it comes down to two things – the reactions used, and the overall synthetic strategy.  Use them in the correct manner, and it comes across as the sweetest synthesis; or alternatively as a [ctrl-C] [ctrl-V] bore-fest;  Garg’s synthesis of Aspidophylline A is most definitely the former.
The target is a member of a large family of alkaloids isolated in 2007, bearing the somewhat unusual furoindoline …

Chemistry World, Still In The RBF »

[5 Jun 2011 | 5 Comments | 10,235 views]
Conophylline

Fukuyama, Tokuyama, Han-ya. ACIEE, 2011, 50, 4884. DOI: 10.1002/anie.201100981
Not a full post, but it’s time to get some of these Chemistry World articles on here.  This once is the most recent, in the June issue, and follows Tohru Fukuyama’s synthesis on Conophylline – a really neat piece of work, especially when you consider how sensitive some of the functionality here is.  How many of you knew of the Polonovski-Potier reaction?

Still In The RBF »

[25 Jul 2010 | 13 Comments | 15,214 views]
Galbulimima Alkaloids (-)-GB 13 and (+)-GB 16

Ma, Zi, Yu. ACIEE, 2010, EarlyView. DOI: 10.1002/anie.201002299.
Why make one natural product when you can make two just as easily?  Or three in this case, but the headline syntheses are the Galbulimima Alkaloids GB-13 and GB-16 – notable members of a family that is getting some serious attention in pharma – one analogue is currently in phase III trials.  With all that potential, it’s not surprising that these beasties have seen quite a bit of synthetic attention; indeed, GB-13 was one of the first syntheses I …

Still In The RBF »

[24 Jun 2010 | 29 Comments | 17,246 views]
Fastigiatine

Shair, Liau, JACS, 2010, ASAP DOI: 10.1021/ja104575h.
After wading through the Heathcock paper last week, I’m glad that today’s topic of discussion is a little shorter and easier to read.  (Seriously, part of me hates reading paper older that the 90′s as the style used in the schemes and figures is so difficult to follow.  Some of those 1960′s JACS papers are a real slog to get through – but worth it, normally….)
The target of choice today is Fastigiatine, a member of the Lycopodium alkaloid family, a popular …

Still In The RBF »

[23 May 2010 | 4 Comments | 9,338 views]
Complanadine A part II

Siegel, Yuan, Chang, Axelrod, JACS, 2010, 132, 5924 DOI: 10.1021/ja101956x.
It’s finally time to examine the second synthesis of Complanadine A, and I have to say that this route couldn’t be further removed from the Sarpong synthesis.  Of course Siegel’s route takes advantage of the dimeric nature of the target, but it’d be more worrying if he didn’t.
The synthetic action begins with a rather nice alkylation. Starting with a unsymmetrical cyclohexanone, alkylation could have occurred on either (or both) sides of the carbonyl.  By using a sulfide, the deprotonation is …

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[28 Mar 2010 | 14 Comments | 17,101 views]
Actinophyllic Acid

Overman, Martin, Rohde. JACS, 2010, ASAP. DOI: 10.1021/ja100178u.
I don’t think there is a single academic whose syntheses I look forward to more than Larry Overman.  I’m not sure exactly why that it, but I think the main reason is the overall standard of his work, as well as his tendency to write fascinating and informing full-papers.  He’s also one of those professors who ‘owns’ a particular type of natural product; ‘Overman molecules’ are of course, alkaloids.
This paper not only discusses a ‘first synthesis’ in a racemic form, but also a …

Still In The RBF »

[24 Jan 2010 | 62 Comments | 23,901 views]
Crambidine

Gin, Perl, Ide, Prajapati, Perfect, Duron. JACS, 2010, ASAP. DOI: 10.1021/ja910831k.
When I see targets containing guanidine moieties these days, I immediately think of David Gin, which goes to show how much he owns that motif just now.  Looking back into the murky past of Tot Syn, an earlier post covered Gin’s synthesis of Batzelladine A, which was fairly guanidine-tastic.  This bad-boy only has one, but with a bit of “anticancer, anti-HIV, antifungal, and Ca2+ ion channel blocking [activity]“, that grant-form presumably filled itself, especially at MSKCC.  However, …

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[6 Sep 2009 | 31 Comments | 17,727 views]
Minfiensine

MacMillan, Jones, Simmons. JACS, 2009, ASAP. DOI: 10.1021/ja9052366.
Now this is a popular target; I’ve covered syntheses by both Qin and Overman (with a related synthesis of vincorine by Qin too), both of which contain some really nice chemistry, and aren’t exactly lengthy.  However, this approach by MacMillan is incredibly concise, containing only nine steps, and starting with a commercially available indole.  To get to the key cyclisation precursor, a process of carbonylating the C-2 position by lithiation and addition of DMF, followed by a Horner-Wadsworth-Emmons olefination …