Production of fructose in seminal fluid is by following steps
Glucose-6-phosphate>glucose>Sorbitol>Fructose 

Fructose can be synthesis from glucose or glycogen. The pathway is :-
Glucose-6-phosphate > fructose-6-phosphate > fructose
Glucose-6-phosphate > sorbitol phosphate > fructose phosphate > fructose
Glucose-6-phosphate > glucose > sorbitol > fructose
Glucose-6-phosphate > fructose- 1 -phosphate > fructose