The Synthesis of Optically Active P‐Phenyl‐P‐(2,4,6‐trimethylphenyl)phosphinamide and an X‐Ray Structure of (‐)‐(1R)‐N‐(1‐Phenylethyl)‐(SP)‐P‐phenyl‐P‐ (2,4,6‐trimethylphenyl)phosphinamide.