Cyclopamine analogs

A compound represented by the following structure:

• or a pharmaceutically acceptable salt thereof;
• wherein:
• R1 is H, alkyl, —OR, amino, sulfonamido, sulfamido, —OC(O)R5, —N(R5)C(O)R5 or a sugar;
• R2 is H, alkyl, alkenyl, alkynyl, aryl, cycloalkyl, nitrile, or 3-7 membered heterocycloalkyl that includes from 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur;
• or R1 and R2 taken together form ═O, ═S, ═N(OR), ═N(R), ═N(NR2), or ═C(R)2;
• R3 is H, alkyl, alkenyl, or alkynyl;
• R4 is H;
• alkyl;
• alkenyl;
• alkynyl;
• aryl;
• cycloalkyl;
• 3-7 membered heterocycloalkyl that includes from 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur;
• aralkyl;
• 5-6 membered heteroaryl that includes from 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur;
• heteroaralkyl, wherein the heteroaryl portion is a 5-6 membered heteroaryl that includes from 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur;
• haloalkyl;
• —OR;
• —C(O)R5;
• —CO2R5;
• —SO2R5;
• —C(O)N(R5)(R5);
• —[C(R)2]q—R5;
• —[(W)—N(R)C(O)]qR5;
• —[(W)—C(O)]qR5;
• —[(W)—C(O)O]qR5;
• —[(W)—OC(O)]qR5;
• —[(W)—SO2]qR5;
• —[(W)—N(R5)SO2]qR5;
• —[(W)—C(O)N(R5)]qR5;
• —[(W)—O]qR5;
• —[(W)—N(R)]qR5;
• —W—NR3+X−;
• or —[(W)—S]qR5;
• wherein each W is, independently, a diradical;
• each q is independently for each occurrence 1, 2, 3, 4, 5, or 6;
• X− is a halide;
• each R5 is, independently, H;
• alkyl;
• alkenyl;
• alkynyl;
• aryl;
• cycloalkyl;
• 3-7 membered heterocycloalkyl that includes from 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur;
• aralkyl;
• 5-6 membered heteroaryl that includes from 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur;
• heteroaralkyl, wherein the heteroaryl portion is a 5-6 membered heteroaryl that includes from 1-4 heteroatoms independently selected from nitrogen, oxygen, and sulfur;
• or —[C(R)2]p—R6;
• wherein p is 0-6;
• or any two occurrences of R5 on the same substituent can be taken together to form a 4-8 membered optionally substituted ring which contains 0-3 heteroatoms selected from N, O, S, and P;
• each R6 is independently hydroxyl, —N(R)COR, —N(R)C(O)OR, —N(R)SO2(R), —C(O)N(R)2, —OC(O)N(R)(R), —SO2N(R)(R), —N(R)(R), —COOR, —C(O)N(OH)(R), —OS(O)2OR, —S(O)2OR, —OP(O)(OR)(OR), —NP(O)(OR)(OR), or —P(O)(OR)(OR);
• each R is independently H, alkyl, alkenyl, alkynyl, aryl, cycloalkyl or aralkyl;
• provided that when R2, R3, and R4 are H;
• R1 is not hydroxyl or a sugar;
• further
• provided that when R4 is hydroxyl, then R1 is not a sugar or hydroxyl;
• further
• provided that when R4 is hydroxyl, then R1 and R2 together are not C═O.