Good point. I should have explained better (it all made sense in my head!)
In the first chart, molecules are grouped vertically by oxidation level, not by pKa. All molecules in the same column are "at the same oxidation level." Alkenes are at "the same oxidation level" as alcohols. Acids, esters, amides are all "at the same oxidation level" but are not as oxidized as carbonates or CO2
. You can (theoretically) interconvert between any two molecules in the same column by using acid/base chemistry (thus vertical movements are not oxidations which is why these molecules are "at the same oxidation level.") Add HCl to an alkene (acid/base chemistry) to get an alkyl halide. All carboxylic acid derivative interconversions are acid/base chemistry (add H2
and methanol to an acid to get an ester). But to convert an ester to an aldehyde, I have to reduce with a hydride source.
In the top chart, to move horizontally, you have to use a redox reaction (you don't have to stay in the same row, but it needs to be a redox reaction). To move vertically within a column, you have to use an acid/base reaction.
In the second chart, there is no y-axis anymore. Vertical groups of molecules all have the same numeral oxidation state of carbon, but an organic chemist would not say that any vertical group of molecules are "at the same oxidation level."
That's the dichotomy I'm pointing out. I guess my point was, the top chart was a chart my prof gave us in my advanced organic class in grad school. It's a handy chart to determine what 'classification' of reaction I need to use. If I want to move vertically within a column, I only need acid/base reactions. If I want to jump to another column, I need redox chemistry. And this is true. If I have an alkene and I want an epoxide, I need to oxidize. If I have a ketone and I want an acetal, I need alcohol and acid. When you start actually calculating out the actual oxidation number of carbon in these functional groups, I realized it depended on more than the heteroatom. It depended on the rest of the hydrocarbon framework. Suddenly, things that were 'at the same oxidation level' before now had completely different actual oxidation states of carbon. This confused me at first and I didn't like it. So I drew out two big charts, pondered, sobbed for a while, had lunch, taught class, came back here and posted the charts to see what others thought
(In both charts, horizontal groupings are arbitrary based on molecules that "look alike" (hydrocarbons, halides, nitrogen-containing).)