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I have been reading through Philip J. Kocienski's book Protecting Groups to try to better understand some of the characteristics of hydroxy protecting groups. I am looking to understand the compatibility of silyl ethers, alkyl ethers, alkoxymethyl ethers, tetrahydropyranyl, methylthiomethyl ethers, esters, and carbonates with acidic conditions; however, my book is very vague on this. Which of these classes of protecting groups will be compatible with strongly acidic conditions (specifically, I will need it to remain intact in HBr for an addition reaction). I am just looking to know which categories are best for these conditions so I can narrow my search. So far, based on what I have read, the Troc protecting group would best suit strongly acidic conditions; however, it is highly electron withdrawling, which will likely affect an addition reaction I am looking to perform.

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    $\begingroup$ At what temperature will the HBr reaction be run? $\endgroup$ – Waylander Nov 11 '19 at 8:04
  • $\begingroup$ I will be running the reaction at -10 C in a 30% HBr-acetic acid solution in toluene (an adaption of the following protocol: pubs.acs.org/doi/pdf/10.1021/ed072p848). All future steps are also performed at -10 C. $\endgroup$ – Eli Jones Nov 11 '19 at 14:27
  • $\begingroup$ Plain old O-benzyl ether will probably stand that pretty well $\endgroup$ – Waylander Nov 11 '19 at 14:55
  • $\begingroup$ Well "protective groups" are not an absolute way of protecting a moiety. It always depends on the reaction conditions you will use later. $\endgroup$ – SteffX Nov 11 '19 at 15:34
  • $\begingroup$ I cannot use a benzyl ether since the product I have to deprotect (I've included an image above - the aliphatic -OH group will have the protecting group-) contains a benzyl ether moiety $\endgroup$ – Eli Jones Nov 11 '19 at 15:45

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