B.R.S.M. The Battlefield Earth of organic chemistry blogs

20Feb/1312

Woodward Wednesdays 6: Reserpine (Part 1/2)

I'm going to do this one in two parts, in the hope that posting the first half now will force me to find time to write the second part at the weekend. Also, it'll hopefully make for shorter and more readable posts. Enjoy!

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Reserpine is an indole alkaloid isolated in 1952 from the extract of Rauwolfia sepentina or ‘Indian snake root’, a popular plant in traditional Indian medicine used as a sedative and antipyretic, and reportedly taken by Mahatma Gandhi himself. It's also enjoyed some attention from Western doctors as an antihypertensive and antipsychotic, notably being the first ever drug to successfully demonstrate antidepressant properties in a randomized placebo-controlled trial (although it’s rarely used nowadays because of its numerous side effects, which are as varied as they are unpleasant). Its structure was solved in just 3 years (a remarkably short period for the pre-NMR era) and, when it was finally reported in the summer of 1955, Woodward immediately set to work. By the end of 1956, just a year later, he was able to report a  detailed series of studies culminating in the landmark first total synthesis of the natural product, again pushing forward the complexity limit at which synthetic chemists could operate. In the years that followed, reserpine became a classic target, worked on by some of the greatest chemists of the past 50 years.[1] In fact, it remains a popular molecule to this day, as indicated by a new total synthesis reported just a month or so ago by Jacobsen and co-workers, (Org. Lett., 2013, 3, 706).

Although Woodward’s synthesis of this target, supposedly his personal favourite of all those he masterminded, has been discussed in just about every book to be written on the history of total synthesis, I can’t resist the temptation of writing my own summary of it any longer, so here goes.

Filed under: Total Synthesis, Woodward Wednesdays | 42,374 views | 12 comments Continue reading
7Feb/130

From Pasta to Superconductor In Four Easy Steps

GA

From Chem. Commun., 2013, ASAP (DOI: 10.1039/C3CC38271K)

Seriously. From the abstract:

"Self-supporting superconducting replicas of pasta shapes are reported, yielding products of differing 3D architectures. Functioning high-temperature superconductor wires are developed and refined from replicas of spaghetti, demonstrating a unique sol–gel processing technique for the design and synthesis of novel macroscopic morphologies of complex functional materials."

Huh? And it gets better in the 'General Experimental' section:

"Spaghetti (own-brand durum wheat dried pasta) was purchased from The Co-operative Food (Co-operative Group Limited, UK), penne and fusilli (own-brand durum wheat dried pasta) were purchased from Sainsbury’s (J. Sainsbury’s plc, UK) and HonigTM Samen “Piraten Pasta” was a gift from Jamie Shenston (University of Bristol, UK) and Caroline Walker (Heinz)... Unless stated otherwise, all materials were used as received, and with no further purification."

The pasta is then soaked in a delicious blend of yttrium, barium, copper and silver (until green), oven baked at 920 ºC (gas mark 36, if you're trying this in your oven at home), sintered and annealed to taste then served in liquid helium. Yum!

Thanks to occasional commenter Martyn for pointing this out!

Filed under: Current Literature | 11,509 views | no comments No Comments
6Feb/138

Oh, Sigma…

I'm a little busy with blog-syn and actual work at the moment, but a friend just sent me this screenshot from the Aldrich website, which I think I'll share with you all (annotation his):

sigma

 

Now, correct me if I'm wrong, but if I wanted to report a compound in, say, J. Med. Chem., I'm quite sure that TLC would not be an acceptable proof of purity. And if anyone knows how I can TLC quantitatively, please leave a comment, because I'm getting sick of running all these crude NMRs and HPLCs...

Filed under: Uncategorized | 7,452 views | 8 comments 8 Comments