# Chemistry - Etymology of alanine

## Solution 1:

In the original German paper [1] Adolf Strecker used Aldehyd-Ammoniak or aldehyde-ammonia as a precursor, that's where the name derives from:

Vor einigen Jahren habe ich gezeigt, daſs Aldehyd-Ammoniak und Blausäure beim Erwärmen mit verdünnter Chlorwasserstoffsäure sich zu einer schwachen Basis, Alanin genannt, vereinigen [...]: $$\ce{\underset{\text{Aldehyd-Ammoniak}}{C4H4O2 * NH3} + HCl + \underset{Blausäure}{C2NH} +2 HO = \underset{Alanin}{C6H7NO4} + NH4Cl}$$

As David Richerby mentioned in the comments, Strecker's brutto-formula ($\ce{C6H7NO4}$) deviates from the moden one ($\ce{C3H7NO2}$), also the reaction scheme is a bit different.

1. Strecker, A. Annalen der Chemie und Pharmacie 1854, 91 (3), 349–351. DOI 10.1002/jlac.18540910309.

## Solution 2:

User364914 may be confused by the "odd" formulas in Strecker's 1854 paper. At that time there was no universal agreement on the masses of atoms. Was carbon 6 or 12? Was oxygen 8 or 16? Strecker used 6 for carbon and 8 for oxygen.

The aldehyde is acetaldehyde, $$\ce{NH3}$$ is OK, blausaure is hydrogen cyanide and $$\ce{OH}$$ is water. The corrected structures should have half the number of carbons and oxygens. The modern equation should read:

$$\ce{C2H4O.NH3 + HCl + HCN + H2O -> C3H7NO2 + NH4Cl}$$