This invention relates to a formulation comprising a compound of formula (I) where R1 and R2 are each independently hydrogen, optionally substituted C1-18 alkyl, optionally substituted C1-18 alkenyl, optionally substituted C3-8 cycloalkyl, optionally substituted C3-8 cycloalkenyl or optionally substituted aryl; provided that the total number of carbon atoms in R1 and R2 is an integer from 5 to 40 inclusive; the use of a compound of formula (I) (i) as an adjuvant provided that the total number of carbon atoms in R1 and R2 is an integer from 5 to 40 inclusive; and (ii) as a solvent provided that the total number of carbon atoms in R1 and R2 is an integer from 5 to 20 inclusive; to certain novel compounds of formula (I) and to a process for preparing those novel compounds.