Is acetal a protecting group?
Acetals are used as protecting groups for carbonyl groups in organic synthesis because they are stable with respect to hydrolysis by bases and with respect to many oxidizing and reducing agents.
How can you protect a ketone group?
Cyclic acetals and ketals are the most useful carbonyl (aldehyde or ketone) protecting groups. Common diols used to form ketals are show below in order of their relative rate of formation. 1,3-dioxanes cleave faster than 1,3-dioxolanes. Acetals and ketals are easily formed and cleaved.
What is THP used for?
Trihexyphenidyl is used to treat symptoms of Parkinson’s disease or involuntary movements due to the side effects of certain psychiatric drugs (antipsychotics such as chlorpromazine/haloperidol).
What are good protecting groups?
Common protecting groups
- Acetyl (Ac) – Removed by acid or base (see Acetoxy group).
- Benzoyl (Bz) – Removed by acid or base, more stable than Ac group.
- Benzyl (Bn) – Removed by hydrogenolysis.
- β-Methoxyethoxymethyl ether (MEM) – Removed by acid.
How are acetal type protecting groups deprotected?
Acetal type protecting groups such as methoxymethyl (MOM), 2-methoxyethoxymethyl (MEM), and tetrahydropyranyl (THP) are commonly used for alcohols and phenols. Although many methods to deprotect them have already been reported, 1 most were accomplished under acidic conditions, which often causes adverse reactions.
How is the deprotection of THP ether performed?
The deprotection of THP ether ( 2) and MEM ether ( 3) also proceeded. However, the deprotection of MEM ether required somewhat higher temperatures. In the case of THP ethers, 2- (2-hydroxyethoxy)-1-oxacyclohexane ( 5) was isolated ( Scheme 2 ). For example, the deprotection of THP ether 2a and 2b gave 5 in 75% and 57% yield, respectively.
How is Fmoc-TRP-OH side chain protected with THP?
Although the carboxylic acid reacts with DHP in a similar way, the corresponding hemiacetal ester was not stable to the aqueous work-up, so Thp was cleaved from the carboxyl group. Thus, it can be concluded that Fmoc-Trp-OH can be side-chain protected with Thp without prior protection of the carboxyl group (Scheme 2 ).
What are the advantages of THP in peptide chemistry?
It has several advantages, including low cost, ease of introduction, general stability to most non-acidic reagents, it confers good solubility, and the ease with which it can be removed if the functional group it protects requires manipulation. However, little attention has been paid to Thp in peptide chemistry.