Resolution of 1‐<i>n</i>‐Butyl‐3‐Methyl‐3‐Phospholene 1‐Oxide With TADDOL Derivatives and Calcium Salts of <i>O</i>,<i>O</i>'‐Dibenzoyl‐(2<i>R</i>,3<i>R</i>)‐ or <i>O</i>,<i>O</i>'‐di‐<i>p</i>‐Toluoyl‐(2<i>R</i>,3<i>R</i>)‐tartaric Acid

Abstract

The resolution methods applying (-)-(4R,5R)-4,5-bis(diphenylhydroxymethyl)-2,2-dimethyldioxolane ("TADDOL"), (-)-(2R,3R)-α,α,α',α'-tetraphenyl-1,4-dioxaspiro[4.5]decan-2,3-dimethanol ("spiro-TADDOL"), as well as the acidic and neutral Ca(2+) salts of (-)-O,O'-dibenzoyl- and (-)-O,O'-di-p-toluoyl-(2R,3R)-tartaric acid were extended for the preparation of 1-n-butyl-3-methyl-3-phospholene 1-oxide in optically active form. In one case, the intermediate diastereomeric complex could be identified by single-crystal X-ray analysis. The absolute P-configuration of the enantiomers of the phospholene oxide was also determined by comparing the experimentally obtained and calculated CD spectra.