For example, its not only illegal for someone to make and sell known illegal drugs, but its additionally illegal to make or sell anything that is not the specifically illegal drug but is analogous to it in terms of effect (and especially facets of chemical structure)

Hmm. I'm not familiar with that as a legal doctrine.

kagis

At least in the US

and this may not be the case everywhere

it sounds like there's a law that produces this, rather than a doctrine. So I don't think that there's a general legal doctrine that would automatically apply here.

https://en.wikipedia.org/wiki/Federal_Analogue_Act

The Federal Analogue Act, 21 U.S.C. § 813, is a section of the United States Controlled Substances Act passed in 1986 which allows any chemical "substantially similar" to a controlled substance listed in Schedule I or II to be treated as if it were listed in Schedule I, but only if intended for human consumption. These similar substances are often called designer drugs. The law's broad reach has been used to successfully prosecute possession of chemicals openly sold as dietary supplements and naturally contained in foods (e.g., the possession of phenethylamine, a compound found in chocolate, has been successfully prosecuted based on its "substantial similarity" to the controlled substance methamphetamine).[1] The law's constitutionality has been questioned by now Supreme Court Justice Neil Gorsuch[2] on the basis of Vagueness doctrine.

But I guess that it might be possible to pass a similar such law for copyright, though.