https://doi.org/10.1351/goldbook.H02763
The @C01058@ of a helical, propeller or screw-shaped molecular entity. A right-handed @H02769@ is described as P (or plus), a left-handed one as M (or minus).
H02763-1.png
H02763-2.png
The application of this system to the description of conformations considers the @T06406@ between two specified (fiducial) groups that are attached to the atoms linked by that bond. The sign of the smaller @T06406@ between the fiducial groups defines the @C01063@ of the @H02769@. Rules for the selection of fiducial groups according to @P04854@ are given by R.S. Cahn, C.K. Ingold and V. Prelog, Angew. Chem. 78, 413-447 (1966), Angew. Chem. Internat. Ed. Eng. 5, 385-415, 511 (1966).See also:
axial chirality
, Δ (delta), Λ (lambda)