Upgraded production of (1R,5S)-1-hydroxy-3,6-dioxa-bicyclo[3.2.1]octan-2-one from cellulose catalytic pyrolysis and its detection in bio-oils by spectroscopic methods

Catalytic pyrolysis of cellulose was carried out focusing on the selective production of the anhy-drosugar (1R,5S)-1-hydroxy-3,6-dioxa-bicyclo[3.2.1]octan-2-one (LAC), a promising chiral chemical forapplication in organic synthesis. The catalyst Sn-MCM-41, montmorillonite K10 or aluminum titanatenanopowder was used by a suitable pyrolysis reactor performing the processes at 500◦C and 350◦C. Aftera workup adapted to optimize the production of LAC and to facilitate the following purification, its amountin the produced bio-oil samples was established by1H NMR spectroscopy using the standard-additionmethod. A further quantitative analysis was based on FT-IR technique performed using a CaF2liquid celland employing the calibration-curve method. Both the methods, which do not require any pre-treatmentsteps, provided comparable values (±1%) in terms of LAC abundance in bio-oil samples and validation ofthe FT-IR based method made it a rapid and efficient tool for quantitative LAC detection also without needof carbonyl band deconvolution. The data showed that (i) Sn-MCM-41 promoted the highest LAC produc-tion by pyrolysis at 500◦C (7.6 ± 0.1 wt.% from cellulose), with a lower than 1% decrease in the presence ofthis catalyst after a regeneration cycle, and (ii) the cheap and eco-friendly montmorillonite K10 emergedas the best alternative, with a yield from cellulose of 4.8 ± 0.1 wt.% at 500◦C and 4.6 ± 0.1 wt.% at 350◦C.