Wroblewski, A. E.; Applequist, J.; Takaya, A.; Honzatko, R.; Kim, S. S.; Jacobson, R. A.; Reitsma, B. H.; Yeung, E. S.; Verkade, J. G. published the artcile< Experimental and theoretical study of the structures and optical rotations of chiral bicyclic ortho esters>, Safety of (S)-Dimethyl 2-hydroxysuccinate, the main research area is chiral bicyclic ortho ester preparation; optical rotation chiral trioxabicyclooctane preparation; crystal structure chiral trioxabicyclooctane; mol structure chiral trioxabicyclooctane; induced dipole moment chiral trioxabicyclooctane; asym synthesis bicyclic ortho ester; classical dipole interaction theory trioxabicyclooctane.
Three rigid (-)-1-R-2,7,8-trioxabicyclo[3.2.1]octanes I [R = H (II), Me (III), Ph (IV)] were prepared in high enantiomeric purity from (S)-1,2,4-butanetriol and RC(OMe)3 (same R). The structure of (-)-IV was determined by x-ray crystallog. From the crystallog. data, 4 refined structural models of IV were generated, which differed only in their degree of geometric optimization. Whereas one model is unrestrained, the other models are increasingly restrained to ideal geometry in order to correct the systematically short bonds associated with an unrestrained refinement. Molar rotations were calculated from classical dipole interaction theory with the structural parameters from the 4 models of IV and atom polarizabilities derived earlier. The calculated molar rotations from IV were correct in sign and insensitive to rotations of the Ph group about the C-C bond. The differences between the calculated values and the exptl. rotation decreased to within a factor of 4 concomitantly with the increased level of geometric optimization of the models. The difference between the theor. and exptl. values is attributable to small uncertainties in atom coordinates and atom polarizabilities. Similar results were obtained for II and III with the structural models obtained for IV. The identical signs and similar magnitudes of rotations for II-IV stem primarily from the chiral gauche arrangement of the butane fragment.
Journal of the American Chemical Society published new progress about Crystal structure. 617-55-0 belongs to class esters-buliding-blocks, and the molecular formula is C6H10O5, Safety of (S)-Dimethyl 2-hydroxysuccinate.
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics