Optical resolution of amino acid and hydroxycarboxylic acid esters by complexation with optically active host compounds: a crystallographic result

Selected esters derived from amino and hydroxycarboxylic acids have been resolved by inclusion complexation with optically active host compounds derived from tartaric acid. The crystal structure of the inclusion compound I(R,R)-(–)-trans-2,3-bis(hydroxydiphenylmethyl)-1,4-dioxaspiro[4.4]-nonane·½(methyl 3-hydroxybutanoate) is reported. I[(C₃₃H₃₂O₄)₂·C₅H₁₀O₃] is monoclinic P2₁, a= 9.176(2), b= 39.70(2), c= 9.216(2)Å, β= 119.45(1)°, V= 2923(2)ų. The structure was solved by direct methods and refined to a final R value of 0.037. Host and guest molecules are linked by hydrogen bonding.