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Articles tagged with: rhodium

Still In The RBF »

[3 Mar 2010 | 67 Comments | 23,401 views]
Echinopine A

Nicolaou, Chen, Ding, Richard. JACS, 2010, ASAP. DOI: 10.1021/ja9093988.
As I twittered the earlier today, redrawing KC’s crayonisation of Echinopine A took quite a while – but I think one needs to see both representations to get a feeling for the complexity here.  The unique [3.5.5.7] carbon skeleton is pretty special – apparently enough that no biological rationale is given for this work.  Perhaps I spend too much time looking a biological assay results these days…
So with nothing else for me to witter-on about, I’ll get into …

Still In The RBF »

[26 Sep 2009 | 53 Comments | 19,587 views]
Biyouyanagin A

Xie, Du, Li, Li. ACIEE, 2009, ASAP. DOI: 10.1002/anie.200902908.
A second showing for this complex little target, Zhixiang Xie’s route uses the same end-game as that developed by Nicolaou two years ago.  However, getting to that point is a very different matter, using some quite powerful chemistry.  The RHS of the molecule is a distinct natural product – hyperolactone C, with the LHS also natural – zingiberene.  The latter was produced as in Nicolaou’s paper, but hyperolactone – the more challenging portion – was produced in a rather different …

Still In The RBF »

[21 Apr 2009 | 106 Comments | 43,790 views]
Agelastatin A Pt. 3

Du Bois, Wehn. ACIEE, 2009, EarlyView. DOI: 10.1002/anie.200806292.
Our third visit to this tightly functionalised little molecule (one – Trost, two – Tanaka, Yoshimitsu), that sterotetrad certainly brings in the players.  I’m not going to go into the biology (hit up the Tanaka post for that), so let get straight into the synthesis.  Du Bois kicks off with an opening of an optically active, bicyclic lactam (2-Azabicyclo[2.2.1]hept-5-en-3-one) – which is commercially available, but not exactly cheap.  Good thing the synthesis is so short…  Protection, reductive ring-opening and …