The intramolecular stabilizing effects of O-benzoyl substituents as a driving force of the acid-promoted pyranoside-into-furanoside rearrangement

• Alexey G. Gerbst,
• Sofya P. Nikogosova,
• Darya A. Rastrepaeva,
• Dmitry A. Argunov,
• Vadim B. Krylov and
• Nikolay E. Nifantiev

Beilstein J. Org. Chem. 2025, 21, 2456–2464, doi:10.3762/bjoc.21.187

• stronger in furanosides most probably due to the differences in geometry of 5- and 6-membered aliphatic rings. However, when it comes to the α-galactopyranoside, there might occur a repulsive O1–O2 interaction which is also stronger in the furanoside form. This leads to the increase of its energy and

• by these rings. The results are provided in Table 2. It can be seen that for both α- and β-isomers these characteristic significantly decrease in the furanoside form as compared to the pyranoside counterpart. The explanation for this finding obviously lies in the nature of 6- and 5-membered aliphatic

• rings. The internal C–C–C angles in them differ leading to more freedom for the side substituents in furanosides. This, in our opinion, means that the π–π interactions between the phenyl rings must increase in this case. However, a repulsive interaction that occurs between O-1 and O-2 oxygen atoms in

Organofluorine chemistry: Difluoromethylene motifs spaced 1,3 to each other imparts facial polarity to a cyclohexane ring

• Mathew J. Jones,
• Ricardo Callejo,
• Alexandra M. Z. Slawin,
• Michael Bühl and
• David O'Hagan

Beilstein J. Org. Chem. 2016, 12, 2823–2827, doi:10.3762/bjoc.12.281

• each other in a cyclohexane ring is introduced as a new design strategy which could be applicable to the preparation of polar hydrophobic cyclohexane motifs. Keywords: aliphatic rings; C–F bond; cyclohexane conformation; difluoromethylene group; organofluorine chemistry; Introduction Selective

Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo

• Alireza Shakoori,
• John B. Bremner,
• Mohammed K. Abdel-Hamid,
• Anthony C. Willis,
• Rachada Haritakun and
• Paul A. Keller

Beilstein J. Org. Chem. 2015, 11, 481–492, doi:10.3762/bjoc.11.54

• slightly bent orientation to each other, with the 7-membered ring in the same curved line. The 5-membered tetrahydrofuryl ring is disposed orthogonally to the curved backbone and is in a puckered conformation, typical of 5-membered aliphatic rings. The heterocycle is stable at room temperature and to air