problem to unerstand sterio chemistry

[shani]

I feel real time difficulty to uderstand the steriochemistry and reaction mechanisms in organic chemsitry, is there any one to give some useful tips to have understanding the sterio chemistry as well as reaction mechanisims in organic chemsitry.

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tips to understannd organic reaction mechanism and steriochemistry

[spin-1/2-nuclei]

I feel real time difficulty to uderstand the steriochemistry and reaction mechanisms in organic chemsitry, is there any one to give some useful tips to have understanding the sterio chemistry as well as reaction mechanisims in organic chemsitry.

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tips to understannd organic reaction mechanism and steriochemistry

 

Hi please correct me if I am wrong, but I think you are asking how to understand stereochemistry and reaction mechanisms in organic chemistry. I'm probably not going to be able to give you a complete response, but I will do my best to point you in the right direction.

 

First I will start with mechanisms because once you understand those, it is easier to talk about stereochemistry. Before you attempt to write a mechanism in chemistry you need to understand the following concepts. (This is not all inclusive, but should get you going in the right direction)

 

1. electronic ground state configuration for the atoms and how to assign this

2. understand formal charges and how to compute the # valence electrons

3. hybridization

4. resonance structures

5. sources of electron density and deficiency (nucleophile vs electrophile)

6. HSAB(hard soft acid base) theory

7. pka(s) of the common functional groups

8. leaving group stability

9. solvent

10. Know if a step in your mechanism is reversible or not

11. be aware of any possible competing reaction pathways

 

Once you have all of that information, the first thing you do is identify the functional group on your molecule that is the most reactive for the particular type of reaction and the conditions. (i.e. SN1, or rearrangement reaction, or acid base reaction etc). Next you make sure to move electrons towards a source of electron deficiency and be mindful of octets, make sure to place negative charges on the most electronegative atom and positive charges on the least, also be sure to pay attention to the pka(s) of acids and bases remembering that equilibrium lies in the direction of the weakest acid.

 

We can try a few mechanisms if you'd like: Here are a couple of questions you can do if you want and I will check out your answers and walk you thought them if you've made any mistakes.

 

1. Fischer Esterification of Benzoic acid with H2SO4 and excess ethanol.

2. Aldol condensation of Acetophenone and benzaldehyde

3. T-butyl chloride with phenoxide (will this be an SN1, SN2, E1, or E2? Why?)

 

In order to understand stereochemistry you must have a good understanding of spatial orientation. There is no way to explain all of stereochemistry in one post, but I can point you in the right direction.

Be sure to be very familiar with the following concepts.

 

1. enantiomer

2. diasteriomer

3. mesocompound

4. isomer

5. R & S

6. relative vs absolute stereochemistry

7. Re face vs Si face

8. chirality & prochiral centers

9. molecular symmetry

10. racemic

11. %ee and %de (enantiomeric and disateriomeric excess)

 

I can't tell from your post what your level of exposure is to stereochemistry, but if you're looking for practice problems let me know and I can PM you links to some good websites with some of these.

 

hopefully this was useful to you.

[Charlatan]

I feel real time difficulty to uderstand the steriochemistry and reaction mechanisms in organic chemsitry, is there any one to give some useful tips to have understanding the sterio chemistry as well as reaction mechanisims in organic chemsitry.

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Merged post follows:

Consecutive posts merged

tips to understannd organic reaction mechanism and steriochemistry

 

You want to 'mix cells' and watch the 'reflexes'? Organs have reflexes, so that is what I call it, by the by...

 

So, if you were to mix cells, there would be no mixing as they both have mass of a solid form, even the liquids don't penetrate them. Cells are programmed to react with other cells through impulses and are muscles so are trained to repeat said exercises, as no organic mass is static. They work off of relationships that they develop with other cells, like a 'spasm'.

[Guest Barryw]

Hi,

 

 

I understand your problem you can consult your teacher regarding your problem stereo chemistry is different from other chemistry so you should consult any of your friend or teacher because it can't be explained in short for it you have to go in detail

 

Thanks,

 

________________--,,

 

 

MSDS Software

[hermanntrude]

A real help in understanding stereochemistry is to use a molecular modelling kit. If you dont have one or can't afford one, many institutions (schools, colleges, universities) will allow you to borrow one for a while. If that isn't true, try using cocktail sticks and pieces of sticky tack. Use coloured markers to distinguish between cocktail sticks