Systematic conformational analysis. A microcomputer method for the semiquantitative evaluation of polycyclic systems containing five-, six- and seven-membered rings. 1. Program characteristics.

Abstract A computer program for the semiquantitative conformational evaluation of polycyclic systems, with focus on five-, six- and seven-membered carbocycles, is described. Starting from two-dimensional structural information of the product as input, the progam deduces the preferred geometry of the molecule, including conformer population distributions when the product is a conformational mixture. Relative enthalpy, entropy and relative free energy terms are also computed for the analyzed product. The SCA program is written in BASIC and has been designed for operation on microcomputer systems.

[1]  D. F. Bocian,et al.  Conformational structure and energy of cycloheptane and some related oxepanes , 1977 .

[2]  C. Romers,et al.  The pseudorotation of cycloheptane—I , 1975 .

[3]  N. L. Allinger,et al.  Conformational analysis—LXXIX , 1972 .

[4]  James B. Hendrickson,et al.  Molecular geometry. V. Evaluation of functions and conformations of medium rings , 1967 .

[5]  E. Corey,et al.  Computer-assisted synthetic analysis. A rapid computer method for the semiquantitative assignment of conformation of six-membered ring systems. 2. Assessment of conformational energies , 1980 .

[6]  N. L. Allinger,et al.  Conformational analysis. LXXXIV. Study of the structures and energies of some alkenes and cycloalkenes by the force field method , 1972 .

[7]  S. Winstein,et al.  Neighboring Carbon and Hydrogen. XIX. t-Butylcyclohexyl Derivatives. Quantitative Conformational Analysis , 1955 .

[8]  C. Altona,et al.  Conformation of non-aromatic ring Compounds—XXV: Geometry and conformation of ring D in some steroids from X-ray structure determinations , 1968 .

[9]  Kazuo Ito.  On the Heats of Formation and Potential Barriers for the Internal Rotation in Hydrocarbon Molecules , 1953 .

[10]  N. Cohen,et al.  Script: interactive molecular geometrical treatments on the basis of computer-drawn chemical formula , 1981 .

[11]  P. D. Clercq,et al.  Systematic conformational analysis. torsion constraint evaluation in cyclic systems , 1981 .

[12]  E. Corey,et al.  Computer-assisted synthetic analysis. A rapid computer method for the semiquantitative assignment of conformation of six-membered ring systems. 1. Derivation of a preliminary conformational description of the six-membered ring , 1980 .

[13]  A. McPhail,et al.  Sesquiterpenoids — XVI: Conformations of cycloheptane and α-methylene-γ-lactone rings in sesquiterpenoids: X-ray determination of the constitution, absolute stereochemistry, and conformation of euparotin bromoacetate , 1973 .

[14]  D. F. Bocian,et al.  Vibrational spectra, potential functions, and conformations of cycloheptanone , 1977 .

[15]  J. B. Hendrickson,et al.  Molecular geometry. VI. Methyl-substituted cycloalkanes , 1967 .

[16]  N. L. Allinger,et al.  Conformational analysis. LXIV. Calculation of the structures and energies of unsaturated hydrocarbons by the Westheimer method , 1968 .

[17]  W. Bauer,et al.  Conformations of Substituted Cyclopentanes. II. Maximally Puckered Envelope and Half-chair Models for Fused Ring Systems , 1962 .

[18]  F. Johnson.  Allylic strain in six-membered rings , 1968 .

[19]  P. Gund,et al.  Three-dimensional molecular modeling and drug design. , 1980, Science.

[20]  D. Cremer,et al.  General definition of ring puckering coordinates , 1975 .

[21]  N. L. Allinger.  Calculation of Molecular Structure and Energy by Force-Field Methods , 1976 .

[22]  K. Pitzer,et al.  The thermodynamic properties and molecular structure of cyclohexane, methylcyclohexane, ethylcyclonexane and the seven dimethylcyclohexanes. , 1947, Journal of the American Chemical Society.

[23]  G. Buemi,et al.  Molecular conformation of cyclenes. I. Cyclohexene, cycloheptene, cis- and trans-cyclooctene, cis- and trans-cyclononene , 1968 .

[24]  W. Donath,et al.  Conformations and Strain Energy of Cyclopentane and its Derivatives , 1959 .

[25]  C. Foces-Foces,et al.  A model for describing the conformations of flexible 6-membered rings—I : The non-chair conformations , 1977 .

[26]  Norman L. Allinger,et al.  Conformational analysis. LX. Improved calculations of the structures and energies of hydrocarbons by the Westheimer method , 1968 .

[27]  S. Malhotra,et al.  Steric Interference in Allylic and Pseudo-Allylic Systems. I. Two Stereochemical Theorems , 1965 .