Correction to: Nature Protocols https://doi.org/10.1038/s41596-018-0121-7, published online 18 February 2019.

The version of this article initially published contained several errors and omissions. Monomer structures M2 and M4 were incorrect in Fig. 4 and Supplementary Fig. 1; the methyl group was in the 3 position instead of the 5 position. In Supplementary Fig. 2, in each of the two hydroxymethylation structures, “OMe” was in parentheses instead of “MeO”. In the Reagents list, manufacturer information was missing for ammonium formate and Celite and the entry for chloroform was missing. In the Equipment section, the entry for a 2L filter flask was missing. In Reagent setup, under “Bulk biomass extractives removal and drying”, the intended Step 6 was missing. In Equipment setup, item 2 under “Automated column machine: silica gel column”, the second bullet point should have read “After loading the sample, run the initial solvent conditions (1 column volume)” instead of “After loading the resting phase at the initial solvent conditions (1 column volume)”. In the table under “Monomer yield quantification using gas chromatography”, the row for septum purge flow was missing, and the values listed for injection temperature, column temperature, carrier gas, FID detection temperature and FID gases were incorrect. In the table under “HSQC-NMR”, the descriptor “channel 2” was missing for what are now shown as O2P and SW2 (originally O1P and SW, respectively), and new rows have been inserted for O1P and SW1. In Box 3, the intended Step 9 was missing. In Box 4, CRITICAL notes were missing for Steps 9 and 23. In Eqs. 7 and 8, “1 −” was missing. In Eqs. 9 and 10, the multiplicative term “1 L” should have been “0.5 L”, and the dilution factor term in Eq. 10 was incorrectly located as the furfural and HMF concentrations were determined by HPLC and are not diluted. In Eq. 11, “mmbiomass” should have been “mBMB”. In Tables 7 and 8, the retention time for M9 should have been 8.796, not 8.976.

The errors have been corrected in the HTML and PDF versions of the article and the Supplementary Information file has been replaced online.