14-methyl epothilone derivatives

A compound of the formula:

• including stereoisomeric forms where the stereochemistry is not shown,
• X7 represents OR or NR2 wherein R is H or alkyl, or is OCOR or OCONR2 wherein R is H or alkyl, or X7 taken together with X9 forms a carbonate or carbamate cycle, and wherein the remaining substituent on the corresponding carbon is H;
• X9 represents ═O or a derivative thereof, or H,OR or H,NR2 wherein R is H or alkyl, or is H,OCOR or H,OCONR2, wherein R is H or alkyl, or represents H,H or wherein X9 together with X7 or with X11 can form a cyclic carbonate or carbamate;
• X11 is ═O or a derivative thereof, or H,OR, or H,NR2 wherein R is H or alkyl, or is H,OCOR or H,OCONR2 wherein R is H or alkyl, or is H,H or wherein X11 in combination with X9 may form a cyclic carbonate or carbamate;
• R12 is H,H, or H, Me,
• X13 is ═O or a derivative thereof, or H,OR or H,NR2 wherein R is H or alkyl, or is H,OCOR or H,OCONR2 wherein R is H or alkyl;
• wherein optionally H or another substituent may be removed from positions 12 and 13 and/or 8 and 9 to form a double bond, wherein said double bond optionally is an epoxide,
• provided that
• if X7 is OH, then either at least one of X9 and X11 is not H, H, or there is no double bond or an epoxide at positions 12 and 13;
• if X9 is H,H, then either X7 is not OH, or X11 is not H,H, or there is no double bond or an epoxide at positions 12 and 13;
• if X is H,H, then either X7 is not OH, or X9 is not H,H, or there is no double bond or an epoxide at positions 12 and 13;
• and
• if there is a double bond or an epoxide at positions 12 and 13, then either X7 is not OH, or at least one of X9and X11 is not H,H.