Smith, Dong, Brenneman, Fox. JACS, 2009, ASAP. DOI: 10.1021/ja9052366.
Read the first post?  Good.  Let’s get on with the one remaining fragment, a further DHP.  Work on this fragment was conducted via a coupling of an enone with the ready-elaborated sidechain – reaction that might be a little sluggish, as the enol functionality is again working against the group.  However, forming a cuperate of the vinyl bromide solved this, allowing a highly selective and reasonably high yielding reaction (60%, 20:1 d.r.).  BTW, the two fragments weren’t particularly …

Smith, Dong, Brenneman, Fox. JACS, 2009, ASAP. DOI: 10.1021/ja9052366.
I thought I’d re-start after holiday with a tasty target, and sorangicin A certainly fits the bill.  It’s not often that I have to draw such an exotic structural motif into a target (though in reality it’s not far removed from a DHP); always a welcome feature in a synthesis.  But sorangicin A is more than just a structural challenge – it’s quite an antibiotic, with broad-spectrum activity against both Gram-positive and Gram-negative strains.  With the funding proposal …

Davies, Williams, Schwartz, Denton, Lian. JACS, 2009, ASAP. DOI: 10.1021/ja9019484.
Now that’s a substituted ring…  done and dusted by Huw Davies and Craig Williams as a collaborative effort (I’d quite like to know how this worked, as the two groups are quite removed), with Davies weighing in with some smart chemistry for building seven-membered rings.  This clearly critical to the synthesis of such a molecule, but the challenge is the heavy substitution, which has thwarted several groups (including individual efforts).  Whilst this paper doesn’t complete the …