Regioselective hydroxylation, functionalisation and protection of spirolactams II

A compound of formula I:

• wherein R1 and R2 are each independently selected from H, OH or OPR;
• R3 and R4 are each independently selected from H, OH, OPR, ═O, cyano, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted amino or halogen,
• R5 and R6 together are ═O or —O—(CH2)m—, wherein m is selected from 1, 2, 3, 4 or 5;
• or R5 is selected from H. OH, or OPR. and R6 is selected from hydrogen, cyano, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted heterocyclyl,
• with the proviso that at least one of R1, R2, R3, R4 or R5 is OH or OPR;
• PR is an hydroxyl protecting group which can be the same or different on each of R1, R2, R3, R4 or R5;
• the dotted line represents a single or double bond, with the proviso that when both R1 and R2 or R3 and R4 are H then there is a double bond between the two C to which the H are linked;
• Z is —CRaRb)n— wherein n is a number selected from 1, 2 or 3 and Ra and Rb are each independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted aryl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted amino or halogen;
• Y is selected from —O—, —S—, —N(RaRb)— or —C(O)—, wherein Ra and Rb are as previously defined and do not form a cyclic ring;
• W is a group selected from substituted or unsubstituted arylalkyl, substituted or unsubstituted heterocyclylalkyl, substituted or unsubstituted alkenyl;
• or a salt, complex or solvate thereof.