A Case-Study on the Resolution of the 1-i-Butyl-3-methyl-3-phospholene 1-Oxide via Diastereomeric Complex Formation Using TADDOL Derivatives and via Diastereomeric Coordination Complexes Formed from the Calcium Salts of O,O’-Diaroyl-(2R,3R)-tartaric Acids

摘要

The resolution of 1-i-butyl-3-methyl-3-phospholene 1-oxide was studied applying TADDOL [(−)-(4R,5R)-4,5-bis(diphenylhydroxymethyl)-2,2-dimethyldioxolane], spiro-TADDOL ud[(−)-(2R,3R)-α,α,α',α'-tetraphenyl-1,4-dioxaspiro[4.5]decan-2,3-dimethanol], or the acidic and neutral Ca2+ salts of (−)-O,O’-dibenzoyl- and (−)-O,O’-di-p-toluoyl-(2R,3R)-tartaric acid as the resolving agent. The absolute configuration of the P-asymmetric center was determined by CD spectroscopy and related quantum chemical calculations. In one instance, the single crystal of the diasteromeric complex incorporating i-butyl-3-phospholene oxide and spiro-TADDOL was subjected to X-ray analysis which suggested a feasible hypothesis for the efficiency of the resolution process under discussion that may be an example for the “solvent inhibited” resolution.ud