Dear Adam Tillo, this is certainly not a basic / simple question. Principally, both –OH groups in 2-(4-hydroxyphenyl)ethanol (= tyrosol) can be tosylated. I found a reference (A. W. Snow, E. E. Foos, Conversion of Alcohols to Thiols via Tosylate Intermediates, Synthesis 2003, 509–512) in which the tosylation of tyrosol is reported. Surprisingly, tosylation occurs only at the aliphatic –OH group! The product is compound 8 in the paper. The preparation is marked in yellow in the attached pdf.

Dear Prof. Edelmann,

Thank you for your answer. I was actually planning to expand tyrosol with an alkyne chain in reaction as follows in the attachment.

Initially, I intended to alkylate it with bromopentyn. It shows however, to be very volatile and toxic compound to work with.

Tosylates tend to be less volatile and are more electrophilic as compared to halides.

I was wondering if the compund 2 will in this case only alkylate phenol group or, also the alkyl alcohol of tyrosol.

Regarding to the article you attached before, it was indeed quite surprising that only aliphatic -OH got tosylated! Do you think it may follow the same route for my reaction?

Best regards, Adam

Dear Adam Tillo, I'm not sure, but my guess is that the reaction with the alkynyl-substituted tosylate will follow the same route, i.e. alkylation will again take place at the aliphatic –OH group. However, you should just try it out and see what happens. I assume that both products would be new compounds. Good luck!