Complex of Tertiary Acetylenic Alcohol and Brucine or Sparteine. X‐Ray Crystal Structural Study and Application to Optical Resolution

Some tertiary acetylenic alcohols were optically resolved efficiently by complexation with brucine or sparteine. In the latter case, mutual optical resolution of sparteine and the tertiary acetylenic alcohol is possible. For an efficient resolution, the tertiary acetylenic alcohol should have at least one aromatic ring such as phenyl, naphthyl, thienyl as a substituent. The crystal structure of the 1:1 brucine complex and of the 1:1 (‐)‐sparteine complex of (‐)‐l‐(o‐bromophenyl)‐1‐phenyl‐2‐propynol (1a) are reported. In both cases, two hydrogen bonds, magnified image are important to fix the two components at a close position where mutual chiral recognition is efficient.