Facile syntheses, structural characterizations, and isomerization of disiloxane-1,3-diols

In the hydrolysis reaction of dichlorosilanes having an intramolecular coordinating atom, dcisiloxane-1,3-diols, [(OH){o-(CH3)2NCH2-C6H4}RSi]2O(R=CH2CH (1), C6H5 (2), o-(CH3)2NCH2C6H4 (3), Me (4)), were obtained in high yields. The results of the crystal structure analyses of meso-2, rac-2a, rac-2b and 3 are reported. They showed strong intramolecular hydrogen bondings between the hydroxy group and the nitrogen atom. We have also found that the diastereomeric isomerization of meso-2 to rac-2 in CDCl3 solvent containing moisture occurred to result in the 55:45 equilibrium mixtures of the isomers and vice versa.