Chiral Synthesis via Organoboranes. Part 34. Selective Reductions. Part 47. Asymmetric Reduction of Hindered α,β-Acetylenic Ketones with B-Chlorodiisopinocampheylborane to Propargylic Alcohols of Very High Enantiomeric Excess. Improved Work-up Procedure for the Isolation of Product Alcohols.