D-allulose 6-phosphate = keto-D-fructose 6-phosphate
d-allulose 6-phosphate = keto-d-fructose 6-phosphate
D-allulose 6-phosphate = keto-D-fructose 6-phosphate
d-allulose 6-phosphate = keto-d-fructose 6-phosphate