
TY  - JOUR
A1  - Lima, Larissa S. 
A1  - Barbosa, Luiz Cláudio de A. 
A1  - de Alvarenga, Elson S. 
A1  - Demuner, Antônio J. 
A1  - da Silva, Antônio A. 
T1  - Synthesis and Phytotoxicity Evaluation of Substituted <emph type="2">para</emph>-Benzoquinones
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 2003
VL  - 56
IS  - 6
SP  - 625
EP  - 630
KW  - 
UR  - https://doi.org/10.1071/CH02032 
N2  - Sorgoleone (1) is one of the major constituents of sorghum root exudates. Sorgoleone is an allelochemical that reduces the growth of broad-leaf plants. The 3,5-dimethoxybenzylic alcohol (3) was used as starting material for the synthesis of 2-methoxy-6-(non-1-yl)benzo-1,4-quinone (9) in 69% yield. Acetylation of (9) with acetic anhydride gave the triacetate (10) in 82% yield. The triacetate (10) was then converted in two steps in 2-hydroxy-5-methoxy-3-(non-1-yl)benzo-1,4-quinone (11) and 2-acetoxy-5-methoxy-3-(non-1-yl)benzo-1,4-quinone (12) in 8% and 37% yield, respectively. Quinone (11) was obtained also by reaction of (12) with DBU in 63% yield. Alkylation of (3) and oxidation with chromic anhydride formed the new quinones (16) (17) and (18) in 23%, 16% and 12% overall yield, respectively. The effect of these quinones and sorgoleone (1) at concentrations of 5.5 &#956;g g&#8211;1 on the development of radicle and aerial parts of Cucumis sativus, Brachiaria decumbens, Hyptis lophanta, and Euphorbia heterophylla was tested. 
ER  -

