Tuesday, 1 March 2011

A bit of chemistry for a change...

After what can only be described as a rant post yesterday I thought I would actually talk about chemistry today. Everything worked today, I ran an excellent old-school esterification. Bubbling HCl gas (made by adding conc. sulfuric acid to sodium chloride) through a methanol solution of a carboxylic acid for 10 minutes gave 100% yield of the methyl ester I was after. I love chemistry like this.

Anyway, I wanted to mention a total synthesis I found on the RSC website yesterday. As Totally Synthetic has shown, the Cortistatins have been synthesised fairly frequently since their isolation. However, this work by Pauline Chiu from the University of Hong Kong really caught my eye. Every so often I see a synthesis where all the steps just make complete sense to me to the point where I can’t believe no-one has thought of it before. The two-page communication details twelve steps to the pentacyclic core of Cortistatin A which is pretty highly functionalised with a fair amount of stereochemical complexity to boot. Take a look at the full paper for details but the step which really got me was the [4+3] cyclisation of an epoxy enol silane with a diene to form that fused central ring system. 

 It’s one of the first times I’ve seen something like this in my (short) career as a chemist and it inspired me to write this post to show that I am actually a chemist and not just a professional moaner…

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