Compounds of formula I ##STR1## where A is OH, B is H, C.sub.1-4 alkyl optionally substituted by C.sub.1-4 alkoxy carbonyl, C.sub.2-4 alkenyl, CONR.sub.2 or COR.sub.4 R.sub.1 is H, R.sub.2 is C.sub.1-4 alkyl, and R.sub.4 is C.sub.1-4 alkyl, or phenyl, optionally substituted by carboxy have pesticidal and especially fungicidal activity. Many of the compounds are novel and these compounds per se, form part of the invention.