9(11)-unsaturated neuroactive steroids and their methods of use

A compound of Formula (I):

• or a pharmaceutically acceptable salt thereof;
• wherein:
• represents a single or a double bond as valency permits;
• each of R2a, R2b, R4a, R4b, R6a, R6b, R7a, R8b, R12a, and R12b is independently hydrogen, halogen, cyano, nitro, hydroxyl, alkoxy, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted carbocyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, —ORA1, —SRA1, —N(RA1)2, —NHC(═O)RA1, —NHC(═O)ORA1, —S(═O)RA2, —SO2RA2, or —S(═O)2ORA1, wherein each instance of RA1 is independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted carbocyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, an oxygen protecting group when attached to an oxygen atom, a sulfur protecting group when attached to a sulfur atom, a nitrogen protecting group when attached to a nitrogen atom, or two RA1 groups are joined to form an heterocyclic or heteroaryl ring;
• and RA2 is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted carbocyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl;
• each of R11 and R16 is independently hydrogen, halogen, cyano, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted carbocyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl;
• R3 is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted carbocyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl;
• R5 is hydrogen or methyl when both of the are single bonds;
• and when one of the is a double bond, R5 and one of R4a or R4b is absent;
• or R5 and one of R6a or R6b is absent;
• R19 is hydrogen or substituted or unsubstituted alkyl;
• Each of R21a R21b and R21c is independently hydrogen, -substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted carbocyclyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl;
• and
• n is 0, 1, 2, or 3;
• provided that the following compound, and salts thereof, is specifically excluded: