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Photochemische Reaktionen. 92. Mitteilung [1]. Photochemistry of Imidazolides II. C 2 ‐C 3 Cleavage of Carboxylic Acid Chains. A Convenient New Method for the Side‐Chain Degradation of Bile Acids and of Lanosterol
Author(s) -
Iwasaki Shigeo
Publication year - 1976
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19760590814
Subject(s) - chemistry , yield (engineering) , side chain , carboxylic acid , medicinal chemistry , cleavage (geology) , imidazole , hydrogen , hydrogen atom , stereochemistry , organic chemistry , group (periodic table) , materials science , geotechnical engineering , fracture (geology) , engineering , metallurgy , polymer
Irradiation of N‐stearoylimidazole ( 1 ) gave hexadec‐1‐ene ( 4 ) in 45% yield, whereas irradiation of N‐(4‐methylstearoyl)imidazole ( 13 ) possessing a tertiary hydrogen atom γ to the carbonyl group led to 2‐methylhexadec‐1‐ene ( 14 ) in 62% yield. These results are explained by a two‐stage process: acyl migration, followed by Norrish Type II eliminatior. The reaction has been utilized for the side chain degradation of bile acids and of lanosterol, in which the second stage of the reaction was shown to proceed in up to 70% yield.