Grossansätze zur Herstellung von α,α,α',α'-Tetraaryl-1,3-dioxolan-4,5-dimethanolen (TADDOLe): Nützliche Hilfsstoffe für die EPC-Synthese und ihre Struktur im Festkörper

The large-scale preparation of α,α,α',α'-tetraaryl-1,3-dioxolan-4,5-dimethanol derivatives is described. It consists of acetalization of dimethyl tartrate and Grignard addition. The diols 2–12 thus obtained are crystalline and stable. They are useful as versatile auxiliaries for enantioselective reactions and for resolutions by clathrate formation. The X-ray crystal structure of the inclusion compound from one of the TADDOLs and CCl4 is described (6·2 CCl4) and compared with the structures of analogous derivatives, including C2-symmetrical diphosphines. Reference is given to other chiral auxiliaries containing the diaryl-methanol group