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 …

Paterson, Anderson, Dalby, Lim, Genovino, Maltas, and Moessner.ACIEE, 2008, EarlyView. DOIs: 10.1002/anie.200705565, 10.1002/anie.200705566.
Now I’ve been waiting for this ‘un… those of you who have been reading for a while will remember that I used to study at Cambridge University, and shared weekly meetings with the Paterson group. It’s certainly an ambitious target, with 21 stereocenters – and when they started the work, the absolute stereochemistry was yet to be assigned! Plenty of other groups are working on a synthesis of this beast, including …