Home » Archive

Articles tagged with: cyclisation

Still In The RBF »

[28 Jun 2009 | 63 Comments | 40,269 views]
Himandrine

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 …

Still In The RBF »

[16 Mar 2009 | 31 Comments | 14,076 views]
ent-Malbrancheamide B

Simpkins, Frebault and Fenwick. JACS, 2009, ASAP. DOI: 10.1021/ja900688y.
Sometimes, the sweetest syntheses come in the smallest packages, and with only one-and-a-bit pages, this is a very short paper.  However, Nigel Simpkins (now Haworth chair of Chemistry at Birmingham) manages to pack in quite a lot of cool stuff into that modest space.  A quick examination of the structure reveals a similarity to the stephacidin family, which has appeared in two previous posts here, one by Robert Williams, the other by Phil Baran.  However, there doesn’t appear to …

Still In The RBF »

[27 Mar 2008 | 46 Comments | 13,527 views]

Baran, O’Malley, Yamaguchi, Young and Seiple. ACIEE, 2008, EarlyView. DOIs: 10.1002/anie.200801138 10.1002/anie.200705913.
There’s been a bit of excitement in the comments about this synthesis, perhaps because it’s completion hints further towards a synthesis of Palau’amine, an ongoing passion of our community. The target of this synthesis contains the tetracyclic bisguanidine core common to these natural products, including eight contiguous stereocenters, making it quite a challenge. No biological activity is mentioned, but when the molecular architecture is as sweet at that, do you need another …