Compositions and methods for treating CNS disorders

1. A compound of Formula (I-III)

or a pharmaceutically acceptable salt thereof, wherein

m is 0, 1, or 2;

X is —O—;

R 3a is unsubstituted C 1-6 alkyl or C 1-6 alkyl substituted with C 1-6 alkoxy;

R 5 is hydrogen or methyl;

R 1 is substituted or unsubstituted C 1-6 alkyl or substituted or unsubstituted heteroaryl; and

each of R 1a , R 1b , R 2a , R 2b , R 4a , R 4b , R 7a , R 7b , R 11a , R 11b , R 12a , R 12b , R 15a , R 15b , R 16a , and R 16b is hydrogen.

2. The compound or pharmaceutically acceptable salt of claim 1 , wherein m is 0.

3. The compound or pharmaceutically acceptable salt of claim 2 , wherein R 1 is substituted or unsubstituted C 1-6 alkyl.

4. The compound or pharmaceutically acceptable salt of claim 3 , wherein R 1 is methyl.

5. The compound or pharmaceutically acceptable salt of claim 3 , wherein R 3a is C 1-6 alkyl substituted with C 1-6 alkoxy.

6. The compound or pharmaceutically acceptable salt of claim 5 , wherein R 3′ is —CH 2 OMe or —CH 2 OEt.

7. The compound or pharmaceutically acceptable salt of claim 3 , wherein R 3a is unsubstituted C 1-6 alkyl.

8. The compound or pharmaceutically acceptable salt of claim 7 , wherein R 3a is methyl.

9. The compound or pharmaceutically acceptable salt of claim 3 , wherein R 5 is hydrogen in the cis position relative to the C10 hydrogen atom.

10. The compound or pharmaceutically acceptable salt of claim 3 , wherein R 5 is hydrogen in the trans position relative to the C10 hydrogen atom.

11. The compound or pharmaceutically acceptable salt of claim 1 , wherein m is 1.

12. The compound or pharmaceutically acceptable salt of claim 11 , wherein R 1 is substituted or unsubstituted heteroaryl.

13. The compound or pharmaceutically acceptable salt of claim 12 , wherein R 1 is

wherein each instance of R 20 is independently halogen, —NO 2 , —CN, —OR GA , —N(R GA ) 2 , —C(═O)R GA , —C(═O)OR GA , —OC(═O)R GA , —OC(═O)OR GA , —C(═O)N(R GA ) 2 , —N(R GA )C(═O)R GA , —OC(═O)N(R GA ) 2 , —N(R GA )C(═O)OR GA , —S(═O) 2 R GA , —S(═O) 2 OR GA , —OS(═O) 2 R GA , —S(═O) 2 N(R GA ) 2 , or —N(R GA )S(═O) 2 R GA ; substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted C 3-4 carbocyclyl, substituted or unsubstituted 3- to 4-membered heterocyclyl, or optionally two R GA are taken with the intervening atoms to form a substituted or unsubstituted 3- to 4-membered carbocyclic or heterocyclic ring,

each instance of R GA is independently hydrogen, substituted or unsubstituted C 1-6 alkyl, substituted or unsubstituted C 2-6 alkenyl, substituted or unsubstituted C 2-6 alkynyl, substituted or unsubstituted C 3-6 carbocyclyl, substituted or unsubstituted 3- to 6-membered heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, an oxygen protecting group when attached to oxygen, a nitrogen protecting group when attached to nitrogen, or two R GA groups are taken with the intervening atoms to form a substituted or unsubstituted carbocyclic or heterocyclic ring; wherein

(i) when R 1 is

 e is 0, 1, 2 or 3;

(ii) when R 1 is

 e is 0, 1, or 2;

(iii) when R 1 is

 e is O or 1;

(iv) when R 1 is

 n is 0, 1, 2, or 3; and

(v) when R 1 is

 n is 0, 1, 2, 3, or 4.

14. The compound or pharmaceutically acceptable salt of claim 13 , wherein

R 1 is

e is 0 or 1; and

R 20 is —CN or methyl.

15. The compound or pharmaceutically acceptable salt of claim 12 , wherein R 3a is C 1-6 alkyl substituted with C 1-6 alkoxy.

16. The compound or pharmaceutically acceptable salt of claim 15 , wherein R 3a is —CH 2 OMe or —CH 2 OEt.

17. The compound or pharmaceutically acceptable salt of claim 12 , wherein R 3a is unsubstituted C 1-6 alkyl.

18. The compound or pharmaceutically acceptable salt of claim 17 , wherein R 3a is methyl.

19. The compound or pharmaceutically acceptable salt of claim 12 , wherein R 5 is hydrogen in the cis position relative to the C10 hydrogen atom.

20. The compound or pharmaceutically acceptable salt of claim 12 , wherein R 5 is hydrogen in the trans position relative to the C10 hydrogen atom.

21. A compound selected from

 or a pharmaceutically acceptable salt thereof.

22. A pharmaceutical composition comprising a compound or pharmaceutically acceptable salt of claim 1 , and a pharmaceutically acceptable excipient.

23. A method for treating a CNS-related disorder related to GABA function in a subject in need thereof, the method comprising administering to the subject a therapeutically effective amount of a compound, or pharmaceutically acceptable salt thereof, of claim 1 , wherein the CNS-related disorder is a sleep disorder, a mood disorder, a schizophrenia spectrum disorder, a convulsive disorder, a disorder of memory and/or cognition, a movement disorder, a personality disorder, autism spectrum disorder, pain, traumatic brain injury, a vascular disease, tinnitus, or status epilepticus.

24. The method of claim 23 , wherein the CNS-related disorder is a mood disorder, and wherein the mood disorder is depression.

25. The method of claim 23 , wherein the depression is postpartum depression or a major depressive disorder.

26. The method of claim 25 , wherein the major depressive disorder is a moderate major depressive disorder or a severe major depressive disorder.

27. The method of claim 23 , wherein the CNS-related disorder is a movement disorder, and wherein the movement disorder is seizure or tremor.

28. The method of claim 27 , wherein the tremor is essential tremor.