DAT Destroyer Organic Chem #63 - Constitutional Isomers question

Mrhyde

Becoming Dr. Jekyll
DAT Destroyer Organic Chem #63 - Constitutional Isomers question

So I know that the formula for getting the number of stereo centers is 2^n with n being the number of chiral carbons.

I know for number 63, that it is 2^2 = 4 - 1 = 3 since its meso.

BUT I am confused as to how to get the correct number of constitutional isomers ?

Is there a math method that we have in which we can use the answer for the number of stereo isomers in order to derive the number of constitutional isomers ? or is there some type of formula to get the number of constitutional isomers or any tricks ?

Thank you for any help !

orgoman22

DAT DESTROYER
Vendor
10+ Year Member
DAT Destroyer Organic Chem #63 - Constitutional Isomers question

So I know that the formula for getting the number of stereo centers is 2^n with n being the number of chiral carbons.

I know for number 63, that it is 2^2 = 4 - 1 = 3 since its meso.

BUT I am confused as to how to get the correct number of constitutional isomers ?

Is there a math method that we have in which we can use the answer for the number of stereo isomers in order to derive the number of constitutional isomers ? or is there some type of formula to get the number of constitutional isomers or any tricks ?

Thank you for any help !

No. There is no way to tell the exact number of constitutional isomers. Did you know that computer programs have been developed to only ESTIMATE the number !!!!! For example, a compound like C30H44O4N would have billions !!! For the DAT, you might be asked a simple one such as C4H10O. Try it.,,,,,and you will find there are 7 ! For a multiple choice exam it is unlikely you would go over 7 constitutional isomers !!!!

Hope this helps

Dr. Romano

Mrhyde

orgoman22

DAT DESTROYER
Vendor
10+ Year Member
DAT Destroyer Organic Chem #63 - Constitutional Isomers question

So I know that the formula for getting the number of stereo centers is 2^n with n being the number of chiral carbons.

I know for number 63, that it is 2^2 = 4 - 1 = 3 since its meso.

BUT I am confused as to how to get the correct number of constitutional isomers ?

Is there a math method that we have in which we can use the answer for the number of stereo isomers in order to derive the number of constitutional isomers ? or is there some type of formula to get the number of constitutional isomers or any tricks ?

Thank you for any help !
Hope you like the answers, you don't hit like so I don't know. If need more help just ask.

Dr. Romano

Mrhyde
OP

Mrhyde

Becoming Dr. Jekyll
Hope you like the answers, you don't hit like so I don't know. If need more help just ask.

Dr. Romano
Haha I always try to hit the 'like' button , perhaps i may have forgotten on some questions. I really appreciate the help on everything!

So the best way is to just draw out the structures and count them to get the number of constitutionals ?

orgoman22

DAT DESTROYER
Vendor
10+ Year Member
Haha I always try to hit the 'like' button , perhaps i may have forgotten on some questions. I really appreciate the help on everything!

So the best way is to just draw out the structures and count them to get the number of constitutionals ?
Yes but also try to look for different functional groups. For example, if you are able to draw some alcohols there certainly will be ethers. If you can draw some aldehydes there will usually be some ketones.

Hope this helps

Dr. Romano

greyworm

Yes but also try to look for different functional groups. For example, if you are able to draw some alcohols there certainly will be ethers. If you can draw some aldehydes there will usually be some ketones.

Hope this helps

Dr. Romano
One question sir, for #63 can't we also draw an ethyl group coming off this cyclopentane? It would make 1 additional const isomer.