Conformation-Related Reaction Efficiency of Glutarimides with Phenyllithium. Structures of 3,3,5,5-Tetramethylglutarimide and 2-Hydroxy-2-phenyl-3,3,5,5-tetramethyl-6-piperidone. X-ray and Theoretical Study

Abstract

Crystal structures of 3,3,5,5-tetramethylglutarimide [3,3,5,5-tetramethylazacyclohexane-2,6-dione] (8) and the product of its reaction with phenyllithium, 2-hydroxy-2-phenyl-3,3,5,5-tetramethyl-6-piperidone (9), have been determined by X-ray structural methods [(8), monoclinic, P21/c, a = 7.715 (2), b = 11.136 (2), c = 11.707 (2) Å, \beta = 105.63 (3)°; (9), triclinic, P\overline 1, a = 6.1685 (6), b = 11.1475 (10), c = 11.526 (2) Å, \alpha = 117.100 (10), \beta = 103.390(10), \gamma = 91.288 (7)°]. Molecular structures of three different glutarimides are discussed. Their energy optimal structures were determined with the use of ab initio calculations. The results of crystallographic and theoretical studies show that the conformational changes in glutarimide introduced by substitution with methyl groups resulted in electron-charge distribution changes. These differences in charge distribution are the reason for the observed variation in yields of the reaction of glutarimides with phenyllithium.

Solid State Structure and Hydrogen Bonding of Some Cyclic NH Carboximides

“…Among these four compounds only one, the 3-methylglutarimide 9, shows a C(4) ribbon structure (Figure 10) while the remaining three adopt the centrosymmetric R 2 2 (8) dimer structure (Figure 6). Comparison with the few similar structures reported previously (Figure 4) shows that while the 4-ethyl-4-methyl compound 19 [27] and the 3,3,5,5-tetramethyl compound 21 [28] both have dimeric structures similar to 10 and 11, the 4,4-dimethyl compound 20 [29] forms a C(4) ribbon similar to 9. The dimer observed for 12 also contrasts with the ribbon structure reported for the thiomorpholine analogue 22 [30].…”

Flatversustwisted rotamers of 2,4-disubstituted thiazoles: the effect of intermolecular hydrogen bonds

“…6.2 for 2-amino-4-phenylthiazole (Au-Alvarez et al, 1999) and 19.2 for the corresponding hydrobromide monohydrate complex (Form et al, 1974). Substantially larger dihedral angles are observed if the 2-position is substituted by a bulky secondary or tertiary amine (Jain et al, 2000;Maurin et al, 1999;Kutschabsky et al, 1990). For the ®ve Figure 1 A view of the molecular structure of (I) in a projection normal to the mean plane of the chloroaryl group.…”

The Solid-State Structures of Cyclic NH Carboximides

“…Seven structures have been reported for tetra-and penta-substituted glutarimides. Five structures-compounds 226 [194], 227 [195], 228 [180], 229 [196] and 230 [196] (Figure 69) exist as simple R 2 2 (8) dimers of category A. The compounds 231 [196] and 232 [196] exist as linear C( 6) chains of imide NH to remote CN nitrogen hydrogen bonding of pattern E.…”