DERIVATIVES OF ALPHA,ALPHA,ALPHA',ALPHA'-TETRAARYL-2,2-DIMETHYL-1,3-DIOXOLAN-4,5-DIMETHANOL (TADDOL) CONTAINING NITROGEN, SULFUR, AND PHOSPHORUS ATOMS - NEW LIGANDS AND AUXILIARIES FOR ENANTIOSELECTIVE REACTIONS

Alpha,alpha,alpha',alpha'-Tetraaryl-2,2-dimethyl-1,3-dioxolan-4,5-dimethanols are converted to bicyclic phosphites and phosphonites (2a-2e) by reaction with Cl2PR and Cl2POR derivatives. - One or both OH groups of the parent TADDOL can be replaced by Cl (--> 4a, 5a), and the halide in turn substituted by azide (--> 4b, 5b), thiocyanide (--> 6), or sulfide (--> 8). Reduction of the azido group(s) to NH2 and N-alkylation or acylation furnishes a variety of amino alcohols (4c-4f) and diamines (5c-5f), as well as a bis(trifluoroacetamide) (5g). Cyclization of the aminoalcohol (4c) produces a bicyclic system (7), containing a pyrrolidine ring (structure determination by X-ray diffraction). - The new chiral compounds containing nitrogen and phosphorus atoms might be useful ligands and auxiliaries for enantioselective syntheses.