83923-88-0Relevant articles and documents
A Novel Synthesis of Precocenes. Efficient Synthesis and Regioselective O-Alkylation of Dihydroxy-2,2-dimethyl-4-chromanones
Timar, Tibor,Jaszberenyi, J. Csaba
, p. 871 - 877 (2007/10/02)
The reactions of trihydroxybenzenes 1a-c and 3-methylbut-2-enoic acid (2) in a zinc chloride/water/phosphoryl chloride system afford either the new trihydroxyphenylbutenone derivatives 3b,c or dihydroxy-2,2-dimethyl-4-chromanones 4a-c in good yields.Compounds 3b,c can be cyclized in high yields to 4b,c in 5percent sodium hydroxide solution.Regioselective O-alkylation of 4a-c leads to 5a-f in good yields.O-Alkylation of 5a-f, followed by reduction and dehydration, results in the formation of precocene 3 (7d) and its regioisomer 7a-c,e,f.Methylation of 4a-c gives 6g-i.Subsequent reduction and dehydration affords precocene 2 (7h) and its regiosiomers 7g,i.
Analogues of Antijuvenile Hormones
Anastasis, Panayiotis,Brown, Philip E.
, p. 2013 - 2018 (2007/10/02)
Several analogues of precocenes I and II have been synthsized, including derivatives of 6,7-dihydroxy-2,2-dimethylchromen, 7,8-dihydroxy-2,2-dimethylchromen, 7-hydroxy-2,2-dimethyl-6-nitrochromene, and 6-amino-7-hydroxy-2,2-dimethylchromen. 5,6-Dimethoxy-3,3-dimethylindene was also synthesized.Improved procedures for the dehydration of chroman-4-ols to chromens and for the reduction of chroman-4-ones to chroman-4-ols are reported.Analogues have been tested for activity in the brown planthopper Nilaparvatus lugens Stal.None had significant morphogenetic effects, but two possessed insecticidal activity and showed both antagonism and synergism when used in cojunction with permethrin.
