Synthesized (10) on beach in the lab and also pilot plant when I was working in company. The synthesis procedue is reproducible even in a 5 L scale reaction in the lab. 

The starting material L-Xylose canot be abtained from natural substances which results a very high cost of manufacturing in the plant. So I modified the reaction to synthesis (7)  following the patent PCT US9815375 started with L-arabinose, resulting a much less cost. 

The procedue for (10) is not usable for manufacturing in the plant because of high toxicity of HF and low controllability. I synthesized Pyridin-HF salt which is a oil like liquid as F source for this reaction which give a 100% yield.