T 2127 (OTTO) Triethylphosphono acetate, 97% Cas 867-13-0 - used in the synthesis of chiral 2-methylcyclopropanecarboxylic acid from (S)-propylene oxide. T 2127 (OTTO) Triethylphosphono acetate, 97% Cas 867-13-0 - used in the Horner-Wadsworth-Emmons reaction (HWE) or the Horner-Emmons modification.