Dear colleagues,
We need to generate a peptide aldehyde starting from
3-(N-Boc-N-methoxyamino)propionyl-beta-Ala-4-methylbenzhydrylamide resin
(='Weinreb' resin) from BACHEM.
I have retrieved from ABRF archive only 2 relevant records (both '97)
and one of them clearly indicates that recommended cleavage procedure*
failed to yield the product having the expected MS.
*<Cleavage can be effected by treatment of the peptidyl-resin with 5 eq.
of LiAlH4 in THF at 0oC for 30 minutes, followed by hydrolysis with 5%
KHSO4. Yields of aldehydic products are typically in the range of 25 -
40%.>
It is not surprising since under these conditions LAH efficiently
reduces carboxylate and amido carbonyls. Does anyone have experience
with DIBAH (diisobutylaluminium hydride) as cleavage reagent?
Were there any improvements in this field?
Thanks in advance for any advice or reference.
Igor Rodionov
Laboratory of Peptide Chemistry
Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry
6 Science Avenue, Pushchino, Moscow Region
142292, Russian Federation
rodionov@fibkh.serpukhov.su
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