Intermediates for the synthesis of bile acid derivatives, in particular of obeticholic acid

A compound of general formula (I):

• wherein:
• is a carbon-carbon single or double bond;
• R1 is C1-4 alkyl optionally substituted with one or more substituents selected from halo, OR7a and NR7aR7b;
• where each of R7a and R7b is independently selected from H and C1-4 alkyl;
• R2 is ═O or OH or a protected OH;
• R3 is H, halo or OH or a protected OH;
• when is a carbon-carbon double bond, Y is a bond, a double bond, or an alkylene, alkenylene or alkynylene linker group having from 1 to 20 carbon atoms and optionally substituted with one or more groups R13;
• when is a carbon-carbon single bond, Y is a bond, a double bond, or an alkylene linker group having from 1 to 20 carbon atoms and optionally substituted with one or more groups R13;
• each R13 is independently halo, OR8 or NR8R9;
• where each of R8 and R9 is independently selected from H and C1-4 alkyl;
• R4 is halo, CN, C(O)R10, CH(OR10)(OR11), CH(R10)(OR11), CH(SR10)(SR11), NR10R11, BR10R11, C(O)CH2N2, —CH═CH2, —C≡CH, CH[C(O)OR10]2, CH(BR10R11)2, azide or a carboxylic acid mimetic group selected from tetrazole, —C(O)NHSO2R30 and —NHC(O)NHSO2R30;
• wherein R30 is H, C1-6 alkyl or aryl;
• where each R10 and R11 is independently:
• a. hydrogen or
• b. C1-20 alkyl, C2-20 alkenyl or C2-20 alkynyl, any of which is optionally substituted with one or more substituents selected from halo, NO2, CN, OR19, SR19, C(O)OR19, C(O)N(R19)2, SO2R19, SO3R19, OSO3R19, N(R19)2 and a 6- to 14-membered aryl or 5 to 14-membered heteroaryl group, either of which is optionally substituted with one or more substituents selected from C1-6 alkyl, C1-6 haloalkyl, halo, NO2, CN, OR19, SR19, C(O)OR19, C(O)N(R19)2, SO2R19, SO3R19, OSO3R19 and N(R19)2;
• or
• c. a 6- to 14-membered aryl or 5 to 14-membered heteroaryl group either of which is optionally substituted with one or more substituents selected from C1-6 alkyl, C1-6 haloalkyl, halo, NO2, CN, OR19, SR19, C(O)OR19, C(O)N(R19)2, SO2R19, SO3R19, OSO3R19 and N(R19)2;
• or
• d. a polyethylene glycol residue;
• or
• e. when R4 is CH(OR10)(OR11), CH(R10)(OR11), CH(SR10)(SR11), NR10R11, BR10R11, CH[C(O)OR10]2 or CH(BR10R11)2 an R10 and an R11 group, together with the atom or atoms to which they are attached, may combine to form a 3 to 10-membered heterocyclic ring;
• each R19 is independently selected from H, C1-6 alkyl, C1-6 haloalkyl and a 6- to 14-membered aryl or 5 to 14-membered heteroaryl group either of which is optionally substituted with one or more substituents selected from halo, C1-6 alkyl and C1-6 haloalkyl;
• or
• when Y is a double bond, R4 is CH2;
• R5 is H or OH or a protected OH group;
• R6 is ═O;
• or a salt thereof.