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Light‐induced transformation of asarone
Author(s) -
Lander V.,
Schreier P.
Publication year - 1991
Publication title -
flavour and fragrance journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.393
H-Index - 70
eISSN - 1099-1026
pISSN - 0882-5734
DOI - 10.1002/ffj.2730060104
Subject(s) - chemistry , isomerization , alkoxy group , stereochemistry , medicinal chemistry , ether , organic chemistry , catalysis , alkyl
The stability of α‐ (1) and β‐asarone (2) in ethanolic solutions (30 %; 100 %; pH 7; pH3) was studied under daylight conditions over a period of six months. After rapid initial light‐induced isomerization of 1 to 2, a number of (i) oxidation products, i.e. 2,4,5‐trimethoxybenzaldehyde (4); l‐(2,4,5‐trimethoxyphenyl) propan‐2‐one (5); 2,4,5‐trimethoxypropiophenone (6); and (ii) addition products, i.e. l‐ethoxy‐l‐(2,4,5‐trimethoxyphenyl) propane (3); (1 R , 2 R ; 1 S , 2 S )‐l‐ethoxy‐l‐(2,4,5‐trimethoxyphenyl) propan‐2‐ol (7A); (1 R , 2 S ; 1 S , 2 R )‐l‐ethoxy‐l‐(2,4,5‐trimethoxy‐phenyl propan‐2‐ol (7B); (1 R , 2 R ; 1 S , 2 S )‐l‐(2,4,5‐trimethoxyphenyl) propan‐1, 2‐diol (8A); (1 R , 2 S ; 1 S 2 R )‐1‐(2,4,5‐trimethoxyphenyl) propan‐1,2‐diol (8B); as well as (iii) the dimers l‐(2′,4′,5′‐trimethoxyphenyl)‐2‐methyl‐3‐(2,4,5‐trimethoxyphenyl)‐l E ‐pentene (9) and l‐(2′,4′,5′‐trimethoxyphenyl)‐2‐methyl‐3‐ethyl‐lα, 2β, 3α ( H )‐4,6,7‐trimethoxyindane (13) were detected after extractive sample preparation. In addition, three dimers, l‐(2′,4′,5′‐trimethoxyphenyl)‐2‐methyl‐3(2,4,5‐trimethoxyphenyl)‐penta‐1 E , 4‐diene (10); 1 ‐(2′,4′,5′‐trimethoxyphenyl)‐2‐(2,4,5‐trimethoxyphenyl)‐3,4‐dimethylcyclobutane (11) and l‐(2′,4′,5′‐trimethoxyphenyl)‐2‐rnethyl‐3‐(2,4,5‐trimethoxyphenyl) prop‐l‐en‐3‐one (12) were tentatively identified. Identifications were carried out by capillary gas chromatography (HRGC) and on‐line HRGC techniques, i.e. HRGC‐mass spectrometry (HRGC‐MS) and HRGC‐Fourier transform infrared spectroscopy (HRGC‐FTIR) as well as 1 H‐NMR spectroscopy.