Baldwin’s Rules for Ring Closure
In the 1970s, J.E. Baldwin described a set of rules for the ease of ring closure in 3-7 membered rings. These rules covered Exo- and Endo- closure at sp3, sp2 and sp atoms.
The corresponding favorable ring opening transformations may be specified as reactions in the Daylight reaction toolkit.
[O:2]=[C:3][*:4].[H:1][*:5][*:6] Hemiacetal Opening