Open AccessAsymmetrische Katalyse durch Vitamin B₁₂: Isomerisierung achiraler 1,4-Epiperoxide zu optisch aktiven 4-Hydroxycycloalk-2-en-1-onen
Author(s) -
Susi Essig,
Rolf Scheffold
Publication year - 1991
Publication title -
chimia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.387
H-Index - 55
eISSN - 2673-2424
pISSN - 0009-4293
DOI - 10.2533/chimia.1991.30
Subject(s) - isomerization , chemistry , yield (engineering) , medicinal chemistry , cyclopentadiene , optically active , solvent , catalysis , organic chemistry , materials science , metallurgy
Achiral cyclic 1,4-epiperoxides undergo fast isomerization to optically active 4-hydroxycycloalk-2-en-1-ones in presence of catalytic amounts of cob(II)alamin (B12r). Light-induced oxygenation of cyclic conjugated dienes in MeOH to 1,4-epiperoxides followed by isomerization with 0,5 mol-% B12 and 5 mol-% vitamin C in the same solvent allows the conversion of cyclohexa-1,3-diene to (S)-4-hydroxycyclohex-2-en-1-one (yield 50%,ee 17%) and of cyclopentadiene to (S)-4-hydroxycyclopent-2-en-1-one (yield 70%, ee = 17.5%) in one pot.