Understanding Ring Puckering in Small Molecules and Cyclic Peptides

ribose ring puckering

Another method for specifying furanose ring puckering.

A set of pseudorotation coordinates is proposed for characterizing the puckering of the furanose ring. These are defined from the curvilinear displacements of the C1' and C4' atoms from the planar conformation. The present coordinates have some practical advantages over the ones currently used.

Modeling ring puckering in strained systems: application to 3,6-anhydroglycosides.

Different conformations of methyl 3,6-anhydroglycosides with the beta-D-galacto, alpha-D-galacto, and beta-D-gluco configurations were studied by molecular mechanics (using the program mm3) and by quantum mechanical (QM) methods at the HF/- and B3LYP/6-31+G** levels, with and without solvent emulation. Using molecular mechanics, the energies were plotted against the phi, theta puckering coordin...

Modeling of deoxy- and dideoxyaldohexopyranosyl ring puckering with MM3(92).

Extensive variations of the ring structures of three deoxyaldohexopyranoses, L-fucose, D-quinovose, and L-rhamnose, and four dideoxyaldohexopyranoses, D-digitoxose, abequose, paratose, and tyvelose, were studied by energy minimization with the molecular mechanics algorithm MM3(92). Chair conformers, 4C(1) in D-quinovose and the equivalent 1C(4) in L-fucose and L-rhamnose, overwhelmingly dominat...

Rotational Spectroscopy and Ring-Puckering Conformation of 3-Hydroxytetrahydrofuran.

The microwave spectrum of 3-hydroxytetrahydrofuran was recorded using a Fourier transform microwave spectrometer; the rotational constants (MHz) are: A = 5581.8230(7), B = 3638.8316(7), and C = 2924.7410(7). Microwave spectra for four (13)C isotopic species were recorded in natural abundance. Stark effect measurements were used to determine the projections of the dipole moment on the principal ...