Selective distortion of the planar group C α C'(O)O to a chiral flat tetrahedron in the amino acid alanine

Based on a Cambridge Structural Database (CSD) search, a meta‐analysis of 116 structures of alanine H 3 NC α H(CH 3 )C′(O)O and its derivatives H 3 NC α H(CH 3 )C′(O)O(H/R/M), protonated, esterified, or coordinated at the carboxylic group, shows that in the first step of a chirality chain, the L configuration at C α induces ( M ) and ( P ) conformations with respect to rotation around the central C′─C α bond. In the second step, the ( M ) and ( P ) conformations selectively distort the planar carboxylic group C α C'(O cis )O trans to asymmetric flat ( R ) and (S) tetrahedra. High diastereoselectivities are caused by the two players attraction N…O cis and repulsion O trans …C Me , which work together in (L, M , R ) configurations but against each other in (L, P , S ) configurations.