Asymmetric synthesis of 3-butylphthalide using isomannide and isosorbide as chiral auxiliaries

A new approach for asymmetric syntheses of （S） and （R）-3-n-butylphthalide （NBP） is presented. The diastereoselective addition of dibutylzinic to aromatic aldehyde 10 or 11 generated from isomannide- or isosorbide-derived chiral auxiliary afforded S-NBP or R-NBP in high optical yields.

Studies on the Diastereoselective Alkylation Reaction Employing Isomannide and Isosorbide as Chiral Auxiliaries

The studies on the asymmetric alkylation of ester employing D-Isomannide and D-isosorbide as chiral auxiliaries were described. The diastereomeric excess of this reaction was up to 90%.

Samarium diiodide induced asymmetric synthesis of γ-butyrolactone using chiral auxiliaries derived from isosorbide and isomannide

The asymmetric reductive coupling reaction of various acrylates derived from D-isosorbide and D-isomannide with acetophenone mediated by samarium diiodide to give both enantiomers of the optically active γ-butyrolactone was described. The best enantiomeric excess of the products was 60%.