Compounds of general formula (I) wherein L1 is O or N(Rb), or L1 is a bond and R3 is ???C2-4 alkenylenyl-G1 or ???(CH2)2-4-G3 may be prepared using general procedures as outlined in Scheme 3.Compounds of formula (11) can be prepared from compounds of formula (10) wherein R103a and R103b are the same, and are each halogen, usin