Okay, I have the molecule alpha-Tocopherol and I need to name it. I already know the name from Wikipedia:
(2R)-2,5,7,8-Tetramethyl-2-[(4R,8R)-(4…
but I want to know how it was named like that. I don't know which part would have priority, or if the chain would have priority... etc. Can someone please walk me through the steps of naming this compound?
I already have the background on naming simple compounds using IUPAC conventions, along with a stereochemistry background so I know what the R and S mean.
Thanks before hand.
(2R)-2,5,7,8-Tetramethyl-2-[(4R,8R)-(4…
but I want to know how it was named like that. I don't know which part would have priority, or if the chain would have priority... etc. Can someone please walk me through the steps of naming this compound?
I already have the background on naming simple compounds using IUPAC conventions, along with a stereochemistry background so I know what the R and S mean.
Thanks before hand.
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the central building structure is the ring system. its a benzen fused with a pyran hence the name benzopyran. but IUPAC calls that chromene and since there are several possible chromene you have to specify that its the 2H-chromen
btw here's the numbering for the chromen
http://www.chem.qmul.ac.uk/iupac/fusedri…
anyways that stuff has an hydroxy group at position 6, so it's an alcohol, hence the ending -6-ol
plus 4 methyl at the positions 2, 5, 7, 8 hence -2,5,7,8-tetramethyl
plus, unlike chromen, it has 2 hydrogen at position 3 & 4 instead of a double bond, hence -3,4-dihydro
last but not least a 13 carbon atom long side chain at position 2 hence 2-tridecyl
and since this side chain has 3 methyl groups (numbering starts at the chromen) on his own it's 2-(4,8,12-trimethyltridecyl)
without going too much into details, all 'name fragments' are organized according to their priority. then you add the R or S information and you have the name.
btw here's the numbering for the chromen
http://www.chem.qmul.ac.uk/iupac/fusedri…
anyways that stuff has an hydroxy group at position 6, so it's an alcohol, hence the ending -6-ol
plus 4 methyl at the positions 2, 5, 7, 8 hence -2,5,7,8-tetramethyl
plus, unlike chromen, it has 2 hydrogen at position 3 & 4 instead of a double bond, hence -3,4-dihydro
last but not least a 13 carbon atom long side chain at position 2 hence 2-tridecyl
and since this side chain has 3 methyl groups (numbering starts at the chromen) on his own it's 2-(4,8,12-trimethyltridecyl)
without going too much into details, all 'name fragments' are organized according to their priority. then you add the R or S information and you have the name.
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Look up Fischer Projection -- it's the way you tell where atoms are in 3d space, since we can only draw things on paper in 2d.
R and S mean basically "toward you in space" and "away from you in space".
But you can't draw forward and backward in space on paper, so they do things like diagonal lines and dashed lines to show direction (example, tetrahedral carbon)
We normally draw Carbon as
..l
-C-
..l
because we can only draw in 2 dimensions -- however, it doesn't really look like that.
http://upload.wikimedia.org/wikipedia/co…
Hope the links I found help! :)
R and S mean basically "toward you in space" and "away from you in space".
But you can't draw forward and backward in space on paper, so they do things like diagonal lines and dashed lines to show direction (example, tetrahedral carbon)
We normally draw Carbon as
..l
-C-
..l
because we can only draw in 2 dimensions -- however, it doesn't really look like that.
http://upload.wikimedia.org/wikipedia/co…
Hope the links I found help! :)