tranquilo
Bluelighter
Thanks for that...v. interesting 
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AADD Moderators: andyturbo
ISOMERS of mdma...
- Thread starter skittlepig
- Start date
randomblondeboy
Bluelighter
- Joined
- Dec 1, 2000
- Messages
- 1,632
when i first read this thread....i didn't understand it.
more than 2 years later......nup. but good to see phase_dancer still making sense to all the chemical genius' out there.
more than 2 years later......nup. but good to see phase_dancer still making sense to all the chemical genius' out there.
phase_dancer
Bluelight Crew
Enantiomers and Chiral Carbons
OK we'll try using more pictures and less words. Rather than rewrite everything, refer to the above for descriptions, definitions etc.,
Looking at figure 1 below we see that the molecule methane can be represented in several ways. All are technically correct, but d is the most accurate in describing the 3D structure.
Figure 1: Schematic drawings of methane
If we take methane and look at it from any angle we see it forms a perfect tetrahedral shape with it's 4 single bonds.
If we then replace 3 or 4 hydrogens with other groups ( colours representing different groups) we can see that different possibilities exist for their arrangement relative to one another. With 4 different substitutions, one of which may be H, the carbon is said to be Chiral
Figure 2: Looking down H axis on carbon bonded to 4 different groups. H= LIGHT BLUE SPHERE
Now, lets take our carbon bonded to 4 different groups and look at how it applies to the alkyl chain (linear carbon-carbon bonds) on MDA. For the sake of clarity, the methylenedioxbenzene part of the molecule is abbreviated to Ar. Figures 3 & 4 show the d and l isomers respectively.
Figure 3: Propyl (3 carbon)-amine side chain of MDA; d, S or (+)- enantiomer (isomer). Chiral carbon is C2
Figure 4: Propyl (3 carbon)-amine side chain of MDA; l, R or (-)-enantiomer (isomer). Chiral carbon is C2
Here's the MDA molecule as you know it (d-isomer)
Figure 5: d(+)MDA with atoms labeled
Finally, this alternative view of d-MDA can be compared against Figures 3 and 4 to clearly see how the groups are positioned. The only thing which may appear strange is the placement of the hydrogens on the N of the MDA molecule compared to the abbreviated form in Figure 3. This is due to the 3D program adjusting (correctly) for the influence of the aromatic ring when present in the full drawing.
Figure 6: Alternative view of MDA showing dextro-positioning on C2
If this made any sense and there is further interest I'll prepare some diagrams to show how the l and d enantiomers are arrived at by allocation of group priority. It's all pretty simple really and will give a good understanding of molecules with several chiral centers, for which several forms may exist. Suitable molecules with 2 chiral centers permit the separation of single chiral center molecules, otherwise requiring sophisticated chromatographic equipment. MDMA is a good example, only requiring the pure isomer of a common kitchen chemical.
OK we'll try using more pictures and less words. Rather than rewrite everything, refer to the above for descriptions, definitions etc.,
Looking at figure 1 below we see that the molecule methane can be represented in several ways. All are technically correct, but d is the most accurate in describing the 3D structure.
Figure 1: Schematic drawings of methane
If we take methane and look at it from any angle we see it forms a perfect tetrahedral shape with it's 4 single bonds.
If we then replace 3 or 4 hydrogens with other groups ( colours representing different groups) we can see that different possibilities exist for their arrangement relative to one another. With 4 different substitutions, one of which may be H, the carbon is said to be Chiral
Figure 2: Looking down H axis on carbon bonded to 4 different groups. H= LIGHT BLUE SPHERE
Now, lets take our carbon bonded to 4 different groups and look at how it applies to the alkyl chain (linear carbon-carbon bonds) on MDA. For the sake of clarity, the methylenedioxbenzene part of the molecule is abbreviated to Ar. Figures 3 & 4 show the d and l isomers respectively.
Figure 3: Propyl (3 carbon)-amine side chain of MDA; d, S or (+)- enantiomer (isomer). Chiral carbon is C2
Figure 4: Propyl (3 carbon)-amine side chain of MDA; l, R or (-)-enantiomer (isomer). Chiral carbon is C2
Here's the MDA molecule as you know it (d-isomer)
Figure 5: d(+)MDA with atoms labeled
Finally, this alternative view of d-MDA can be compared against Figures 3 and 4 to clearly see how the groups are positioned. The only thing which may appear strange is the placement of the hydrogens on the N of the MDA molecule compared to the abbreviated form in Figure 3. This is due to the 3D program adjusting (correctly) for the influence of the aromatic ring when present in the full drawing.
Figure 6: Alternative view of MDA showing dextro-positioning on C2
If this made any sense and there is further interest I'll prepare some diagrams to show how the l and d enantiomers are arrived at by allocation of group priority. It's all pretty simple really and will give a good understanding of molecules with several chiral centers, for which several forms may exist. Suitable molecules with 2 chiral centers permit the separation of single chiral center molecules, otherwise requiring sophisticated chromatographic equipment. MDMA is a good example, only requiring the pure isomer of a common kitchen chemical.
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Cowboy Mac
Bluelighter
with posts like that phase_dancer, i thought i was reading somewhere else
BigTrancer
Bluelight Crew
- Joined
- Mar 12, 2000
- Messages
- 7,342
P_D kicks ass!
tranquilo
Bluelighter
WOW!
Robot Features
Bluelighter
Top post phase_dancer
/me bows
/me bows
phase_dancer
Bluelight Crew
A couple of corrections and picture updates to above posts.