Polyketides and antibiotics produced by combinatorial techniques

A compound of the formula:

• including the isolated stereoisomeric forms thereof;
• wherein R* is a ethyl substituted at position 2 or methyl each substituted by F, Cl, Br, N3, OH, O-alkyl, S-alkyl, CN, O-acyl, O-aryl, NH2, NH-alkyl or N(alkyl)2;
• or
• wherein R* is ethyl substituted at position 1 by F, and position 2 is unsubstituted or substituted by Br, I, OH, O-alkyl, O-aryl, N3, CN, S-alkyl, or S-aryl;
• or is substituted both at the 1 and 2 positions by OH, or positions 1 and 2 are included in a ring wherein the bridge between positions 1 and 2 is —O—, —NH—, or —N-alkyl-;
• or
• wherein R* is vinyl substituted at position 1 by F, Cl or Br;
• or
• wherein R* is C(O)H, C(O)OH, C(O)O-alkyl, C(O)O-aryl, CONH2, CONH-alkyl, CON-(alkyl)2 or CONH-aryl;
• each of R1-R6 is independently H or alkyl (1-4C) wherein any alkyl at R1 may optionally be substituted;
• each of X1-X5 is independently H2, HOH or ═O;
• or
• each of X1-X5 is independently H and the compound of formula (6) contains a π-bond in the ring adjacent to the position of said X at 2-3, 4-5, 6-7, 8-9 and/or 10-11;
• wherein at least two of R1-R6 are alkyl (1-4C);
• and
• wherein any OH included in X4 may be further substituted with desosamine and/or X5 may be further substituted with cladinose.