216858-90-1Relevant academic research and scientific papers
Diastereoselective synthesis of alliin by an asymmetric sulfur oxidation
Koch,Keusgen, Michael
, p. 668 - 671 (2007/10/03)
L-(+)-Alliin (7) has been synthesized from S-allyl-L-cysteine (3) by an asymmetric sulfur oxidation using tetraisopropyl-ortho-titanate [Ti(O-iPr)4] in equimolar amounts. Chirality of the resulting sulfoxide was guided by either (+)- or (-)diethyl tartrate as chiral auxiliary which led to the (-)- or (+)- isomer of L-alliin (7, 8), respectively. To allow this type of oxidation, the amino acid functions of 3 were protected by a tert.-butoxycarbonyl- and a 9- fluorenylmethyl group. Alternatively, an enzyme catalysed asymmetric sulfur oxidation by cyclohexanone oxygenase was carded out. The products were investigated by 1R, MS and NMR spectroscopy. The ratio between the diastereomers 7 and 8 was determined by HPLC. Also IR spectroscopy allowed an estimation of the approximate ratio 7/8.
