sodium bromide (NaBr), 1-cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethylaminomorpholinocarbenium
hexafluorophosphate (COMU), and trifluoroethylamine hydrochloride
(TFEA·HCl) were purchased from Sigma-Aldrich, Sweden, and used
as received. Sodium hydroxide (NaOH), sodium hypochlorite (NaOCl),
sodium acetate trihydrate, sodium chlorite, ethanol, and acetonitrile
were purchased from VWR, Sweden. Deionized water was used from a laboratory
setup. The birch wood (Betula pendula) was purchased from Fredricsons Trä, Sweden.