Reactions of glycidyl derivatives with ambident nucleophiles; part 2: amino acid derivatives

• Gerald Dyker,
• Andreas Thöne and
• Gerald Henkel

Beilstein J. Org. Chem. 2007, 3, No. 28, doi:10.1186/1860-5397-3-28

• from a weak intramolecular hydrogen bond. According to ab initio calculations for cis-9a, (B3LYP, 6-31G*, zero point energy included) this structure is indeed 1.9 kcal/mol more stable than its exo-oriented conformer and 2.2 kcal/mol more stable than its trans-stereoisomer. Conclusion In summary, we

The vicinal difluoro motif: The synthesis and conformation of erythro- and threo- diastereoisomers of 1,2-difluorodiphenylethanes, 2,3-difluorosuccinic acids and their derivatives

• David O'Hagan,
• Henry S. Rzepa,
• Martin Schüler and
• Alexandra M. Z. Slawin

Beilstein J. Org. Chem. 2006, 2, No. 19, doi:10.1186/1860-5397-2-19

• erythro- and threo- 2,3-difluorosuccinic acids were then prepared. The solid and solution state conformation of these compounds was assessed by X-ray crystallography and NMR. Ab initio calculations were also carried out to model the conformation of erythro- and threo- 1,2-difluoro-1,2-diphenylethane as

• ). Conformational energy calculations on erythro and threo-13 Due to the ambiguous solution state study particularly for erythro-13, ab initio calculations were carried out at the B3LYP//cc-pVTZ level exploring absolute energies of the three staggered conformers of both erythro- and threo- 13 [24][25]. The