Ethyl acetate

Naringenin and alkyl iodides (1-iodoheptane, 1-iodooctane, 1-iodononane, 1-iodoundecane) were purchased from Sigma-Aldrich Co. (St. Louis, MO, USA); hydroxylamine hydrochloride from LOBA Feinchemie GmbH (Fischamed, Austria); anhydrous sodium acetate, potassium carbonate and N,N-dimethylformamide (DMF) from Chempur (Piekary Śląskie, Poland).
Anhydrous ethanol for reactions was prepared according to standard procedures. All organic solvents used for extraction and purification (diethyl ether, hexane, ethyl acetate, methylene chloride, chloroform, methanol) were of analytical grade and were purchased from Stanlab (Lublin, Poland).

Chemoselective protection of amino alcohols with Boc-group was
performed similarly to the reported procedure.^{48 (link)} (S)-2-amino-1-propanol (Apollo Scientific
98%, ee: 97%, 1.04 mL, 1 equiv, mass) was dissolved
in water (MiliQ, 3 mL) and (Boc)₂O (Angene 95%, 3.37 mL,
1.1 equiv) was added dropwise. The reaction mixture was stirred overnight
at room temperature. Afterward, the product was isolated by extraction
with ethyl acetate (Stanlab) and dried under vacuum. The resulting
product in the form of white powder was obtained with 85% yield. The
chemical structure of the product was confirmed via ¹H
NMR analysis. The same procedure was used to synthesize Boc-(R)-2-amino-1-propanol but this time using (R)-2-amino-1-propanol as the reagent.