How to make an equilibrium favours the product you want

SMILES

SMILES (standing for Simplified Molecular Input Line Entry Specification) was developed by researchers in the US government one of whom went on to create a chemoinformatics company that markets tools based upon the language and its derivatives (http://www.daylight.com). 

An excellent set of resources is available in the SMILES homepage on the Daylight website , including a full tutorial. 

In SMILES, atoms are generally represented by their chemical symbol, with upper-case representing an aliphatic atom (C = aliphatic carbon, N = aliphatic nitrogen, etc) and lower-case representing an aromatic atom (c = aromatic carbon, etc). Hydrogens are not normally represented explicitly. Consecutive characters represent atoms bonded together with a single bond. Therefore, the SMILES for propane would simply be:

• CCC

Or 1-propanol would be:

• CCCO

Double bonds are represented by an “=” sign, e.g. propene would be

• C=CC

Parentheses are used to represent branching in the molecule, e.g. the SMILES for Isopropyl alcohol (2-propanol) is:

• CC(O)C

Atoms other than the major organic ones (C, S, N, O, P, Cl, Br, I, B) or ions must be enclosed in square brackets.

Ring enclosures are represented by using numbers to signify attachment points, usually starting at 1. The first occurrence of the number defines the attachment point, and subsequent occurrences indicate that the structure joins back to the attachment point at that position. For example, the SMILES for 

Benzene is as follows (note the small ‘c’ for aromatic carbon):c1ccccc1

We can also use branching from the ring system, e.g.
c1cc(Br)ccc1
represents bromobenzene. 

Note that in many cases there can be several SMILES to represent the same structure – for example, we could alternatively represent bromobenzene as:
c1cccc(Br)c1

So here is a SMILES representation for acetaminophen
c1c(O)ccc(NC(=O)C)c1

:

A nice thing about SMILES is it can easily be stored in text or spreadsheet documents. For example, “SMILES files” containing SMILES, structure names or IDs, and sometimes data are often used to transfer information about structures between computers and scientists. Here is a sample of what a short SMILES file might look like:
c1ccccc1 Benzene
c1cc(Br)ccc1 Bromobenzene
c1c(O)ccc(NC(=O)C)c1 Acetaminophen
It is good to understand how SMILES works, but it is unusual for humans to have to do the job of working out SMILES. Normally conversion to and from SMILES is done by the computer using drawing and depiction tools which are described below.

Sources protected by copyright, we are just reporting infortmations © Copyright 2002-2004 David Wild, email wildd @ umich.edu

Racemic Resolution

Hey fellows!!  Here in this post you can find some notes about racemic resolution, or chiral resolution.  In stereochemistry it is a process for the separation of racemic compounds into their enantiomers.


Just follow the link below and you will find some informations about it:

Racemic_Resolution.pdf (<-- dropbox link)

Esterification
Diastereoisomeric salts
chiral columns

 If someone wants to study it more in deep, I found this video really interesting and clear.

Diastereoisomers

What is a Diastereoisomer? Just follow the link below

Diastereoisomers.pdf

This is a nice video about enantiomers and diastereoisomers, let's take a look at it!

How to distinguish one enantiomer from another

Is there any chemical difference between two enantiomers? NOOOOOO


Se distinguish them just because of a property. You can find it HERE

 

If polarimetry catches your attention here you are a video where polarimetry is explained in a quite good way. 

How to label a chiral center

Here in this link (rules.pdf) you can find the rules of priority to assign the R&S configuration to your enantiomer.

Wittig reaction

Here you are some notes about the wittig reaction.
Following the link: wittig.pdf you can find a brief description of the reaction and its mechanism.

Reductive Amination

 Which one is the best way to synthetize a secundary amine?
----> Reductive Amination.pdf

Following the link ( a dropbox link) you can find some notes about reductive amination, I hope you will find them usefull.