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Preparation of valeric acids, pentenoic acids, and γ‐valerolactones labelled with deuterium
Author(s) -
Tashiro Masashi,
Tsuzuki Hirohisa,
Mataka Shuntaro,
Yonemitsu Tadashi
Publication year - 1991
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.2580290610
Subject(s) - chemistry , valeric acid , deuterium , radiochemistry , organic chemistry , butyric acid , physics , quantum mechanics
[2‐ 2 H 1 ]‐, [2,3‐ 2 H 2 ]‐, [2,2,3‐ 2 H 3 ]‐, and [4,4,5,5,5‐ 2 H 5 ]Valeric acids, and trans ‐ and cis ‐2‐[2‐ 2 H 1 ]pentenoic acid and 4‐[4,5,5‐ 2 H 3 ]pentenoic acid have been synthesized from 2‐bromovaleric acid, trans ‐2‐pentenoic acid, 2,3‐dibromovaleric acid, and 4‐pentynoic acid in 78% to 95% isotopic purity by employing Raney alloys or Aluminium powder in alkaline deuterium oxide. The reductions of trans ‐3‐ and 4‐pentenoic acids, while smoothly proceeding with 10% Pd‐C as an additive in the reaction system, resulted in the formation of deuteriated valeric acid with over‐introduction of deuterium atoms. Use of 3,4‐dibromo‐valeric acid resulted in the dehydrobromination between C‐2 and C‐3 and the subsequent hydrolysis of the bromine at C‐4, to provide γ‐[2,3‐ 2 H 2 ]‐ lactone, which was also prepared from 4‐bromo‐ trans ‐2‐pentenoic acid in higher purity. Levulinic acid involves the incorporation of deuterium atoms at C‐3 and C‐5 upon the treatment with 10% NaOD‐D 2 O, followed by Cu‐Al alloy reduction, affording γ‐[3,3,4,5,5,5‐ 2 H 6 ]valerolactone.