Methyl 6-amino-6-oxohexanoate

Gruber, Tobias; Schofield, Christopher J.; Thompson, Amber L.

doi:10.1107/s1600536812003303

Cited by 1 publication

(1 citation statement)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast to the efficient gand d-lactam preparation, analogous cyclization of the respective racemic aminopimelic acid with subsequent methylation had little success when using activating agents such as 3,4,5-trifluorobenzene boronic acid 17 (no reaction) or SiO 2 18 (10% yield). However, preparation of the dimethyl ester of aminopimelic acid followed by heating in refluxing p-cymene 19,20 gave 1 in reasonable yield (57%, Scheme 2 Synthesis of caprolactam derivatives 1-8.…”

Section: Synthesismentioning

confidence: 99%

Conformational studies on substituted ε-caprolactams by X-ray crystallography and NMR spectroscopy

et al. 2014

Self Cite

View full text Add to dashboard Cite

The synthesis and conformational analysis of e-caprolactams containing a-COOMe group at the C-6 position is described. The influence of different C-2, C-6 and N substituents on ring conformation was studied using X-ray crystallography and NMR spectroscopy. The results provide evidence that all the analysed caprolactams adopt a chair type conformation with a planar lactam. In the 6-substituted caprolactam, the-COOMe residue prefers to reside in an equatorial position, but can be induced to occupy an axial orientation by the introduction of a bulky tert-butyloxycarbonyl (BOC) group on the lactam nitrogen or by C-2/C-3 ring desaturation. The BOC protected caprolactam was found to undergo exchange between two chair forms as detected by solution NMR, one with the C-6 ester equatorial (30%) and the other with it in the axial position (70%); the latter was observed by X-ray crystallography. For the C-2 dithiocarbamate substituted C-6 methyl ester sevenmembered rings, a single chair form is observed for cis-isomers with both substituents equatorial. The analogous trans-isomers, however, exist as two chair forms in a 1 : 1 equilibrium ratio of 1,N C 4 and 4 C 1,N conformers, where either substituent can occupy axial or equatorial positions.

show abstract

Section: Synthesismentioning

confidence: 99%