Catalyzes the conversion of 2-epi-5-epi-valiolone to 2-epi-5-epi-valiolone 7-phosphate. Involved in the biosynthesis of the acarviose moiety of the alpha-glucosidase inhibitor acarbose. 2-epi-5-epi-valiolone + ATP = 2-epi-5-epi-valiolone 7-phosphate + ADP + H(+) Belongs to the ROK (NagC/XylR) family.