Chemist In A Transition State

November 28, 2006

Should I forget about this application?

Filed under: Uncategorized — Tynchtyk @ 6:33 pm

I am applying to 3 universities and today, in the morning I managed to send my supplemental documents(rec.letters, SOP, Transcripts) to the University X( the deadline is December 15). 

 I woke up, printed my SOP and stapled it, putted it with the recommendation letters into an envelope and sealed it up. Only after I already sealed it up I realized that I forgot to sign my SOP. I had to open the envelope, sign the SOP and put it again into a new envelope. Then I went to the post office… immediately upon arriving there I found out that I didn’t know the address where I was going to send my documents. I had to come back and look it(the address)  up on the website of the University X  and again go back to the post office. After about half an hour I finally was able to exchange my application package to a piece of a paper  and felt myself as if I have done a big work(it cost me 1280 rubles which is my two months stipend from the university). But this feeling didn’t last long because only now I have discovered that the X Uni Chemistry Department has a special form for recommendation letters which must have been printed out and filled by the recommenders. I didn’t know this(the information about this is written with very small letters on the website)! I thought that Professors can write in whatever format they like…

Moreover, today  the secretary of one of my recommenders told me that she has deleted an e-mail from another university which asked the Prof. to write a rec. letter for me! She thought that it was a spam!

So my advice for international applicants is this: try to select your recommenders among associate or assistant professors because they are not very busy as Full Profs. and they usually don’t have secretarys who can delete everything without reading. After all, people who read the letters don’t care who the recommender is(is he a very famous or is he a Full Prof, etc).

November 25, 2006

I have nowhere to go

Filed under: Uncategorized — Tynchtyk @ 4:42 pm

 Today I had to get up at 5 am!!! I was waken up by that damn megaphone announcing  that everybody leave the dorm immeadiately. At first I thought that it was an antifire measure and decided  not to believe that woman who was shouting as  mad from the megaphone but my roommate was going out. I asked him to call me after he gets out if there really was a fire. I was almost asleep when he called me and told that I immediately made sure that my ass was in the street as quickly as possible.  I jumped out of bed and rushed along the stairs(I live on the 12th floor) to get outside and to discover that there was neither fire nor  any antifire measures. Instead, there was an explosion on the third floor. We were not allowed in and had to wait outside in the cold weather for an hour, then,  me and my friends were lucky to be able to get into the dorm. After about 4 hours when I was going out to go to the laboratory I found out that hundreds of students were still waiting outside!!!

And just a minute ago, as I was typing the above sentences I received a call from one guy and he told me that all the inhabitants of the dorm are being evacuated again right this moment and maybe no one will be allowed in until tomorrow morning!!! Shit! Shit! Shit!

 And I suspect that I am going to spend the night in the laboratory (if the security will not kick my ass and me out into the street cus everyone must leave the institute after 21:00 ).

UPDATE: http://www.lenta.ru/news/2006/11/25/again/  news from the venue

http://www.iht.com/articles/ap/2006/11/25/europe/EU_GEN_Russia_Dormitory_Blast.php

UPDATE 2: The last evacuation turned out to be an experiment!

http://lenta.ru/news/2006/11/25/training/

Yes! Now I can be confident and go home :-))

November 24, 2006

Gelsemine

Filed under: Chalk Talk — Tynchtyk @ 1:28 pm

Welcome to the Friday Night Retrosynthesis Dear Fellow Chemists!

Tonight we are going to retrosynthesize an alkaloid with exceptional structure. Our target

is a famous alkaloid  Gelsemine.

This awesome alkaloid is one of the most beautiful natural products I have ever seen!

 And it is the beauty of it that attracts us because it doesn’t possess any useful biological

properties.

Here is a quotation from Prof. Danishefsky whose group also synthesized this molecule:

The degree of attention which has been lavished by many laboratories on

total syntheses of Gelsemine surely did not arize from any documented

information suggesting that this alkaloid might have valuable properties.

Actually, reports concerning any biological activity associated

with Gelsemine are at least sketchy and often anecdotal in style. Rather,

the attraction of Gelsemine as a target in total

synthesis has been driven by its fascinating three-dimentional

architecture. It is in the solution of such problems that much new

chemistry is often learnt.”

The introduction couldn’t be better uhm? 

And now… enjoy my retsosynthesis and good night!!!: 

gelsemine.gif

Before you go to sleep I want to share with you an excellent problem based on the syntheses of this alkaloid by the groups of Prof. Danishefsky, Fukuyama and Overman. Enjoy!!! 

BTW, I won the first place in that olympiad where that problem was given:-))

November 20, 2006

Help needed!

Filed under: Organic Chemistry — Tynchtyk @ 2:39 pm

Dear Chemists,

I need your ideas on the following transformation:

help.gif

Metals are Manganese and Rhenium.

How could these ylides be obtained from corresponding tricarbonyls? Will these ylides be stable? Has anyone encountered something similar to this in the literature?  I couldn’t find anything in the literature…

Even if you never saw these kind of things your ideas on how they could be synthesized  will be greatly appreciated. 

If these ylides could be easily synthesized they would greatly lighten my work and life because I am involved  in the synthesis of various cumulene carbene complexes of manganese and rhenium. The known methods(acetylene-vinylidene rearrangement, rearrangement of propargilic alcohols) don’t work very good(the best yield in the acetylene-vinylidene rearrangement with rhenium was 14%, for example).

Thank you.

November 17, 2006

Cephalezomine A

Filed under: Chalk Talk — Tynchtyk @ 2:23 pm

Tonight’s target molecule is Cephalezomine A, a representative of Cephalotaxus family of alkaloids.  Cephalezomine A posseses nanomolecular cytotoxic activity and is an acylated derivative of Drupacine.

Thus, our target becomes Drupacine:

 cephalezomine-aretro.gif

The key step is the Pauson-Khand/Michael cascade, which would in one step install (at least on a paper) the core structure of Drupacine.

The carboxylic acid part and further retrosynthes is up to you.

P.S. Recently, Prof. Gin et. al published the synthesis of Deoxyharingtonine,  another member of this alkaloid family:

deoxyharringtonine.gif

Also, this synthesis was highlighted over at Totally Synthetic.

Go and enjoy reading Paul’s Chemdraw skills and comments by others on this post.

  

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