l; as defined above; --(CHOR1)COOR4 wherein R4 is as defined above; --CHR2 OR1 wherein R1 and R2 are as defined above; --(CHOR1)(CHR2 OR1) wherein R1 and R2 are as defined above; --CH2 O--CO--R4 wherein R4 is as defined above; --(CHOR1)(CH2 R6) wherein R1 is as defined above and R6 is a halogen preferably fluorine, chlorine, iodine or bromine; --CH2 R6 wherein R6 is as defined above; or when R2 is