Lewis acid promoted reactions of ethenetricarboxylates with allenes: synthesis of indenes and gamma-lactones via conjugate addition/cyclization reaction.
Indenes are important core structures in organic chemistry. Few simple arylallenes have been used to construct indene skeletons by Friedel-Crafts reaction. Lewis acid catalyzed reaction of ethenetricarboxylates 1 and arylallenes has been examined in this study. The reaction of arylallenes and ethenetricarboxylate triesters with SnCl(4) gave indene derivatives efficiently, via a conjugate addition/Friedel-Crafts cyclization reaction. On the other hand, the reactions of 1,1-diethyl 2-hydrogen ethenetricarboxylate and arylallenes or alkylallenes with SnCl(4) at -78 degrees C or room temperature and subsequent treatment with Et(3)N gave gamma-lactones. The reactions of triethyl ethenetricarboxylate and 1,1-dialkylallenes with SnCl(4) at room temperature also gave gamma-lactones.
Yamazaki
Shoko
S
Department of Chemistry, Nara University of Education, Takabatake-cho, Nara 630-8528, Japan. yamazaks@nara-edu.ac.jp
Yamamoto
Yuko
Y
Fukushima
Yugo
Y
Takebayashi
Masachika
M
Ukai
Tetsuma
T
Mikata
Yuji
Y
D000143:Acids / Q000737:chemistry*; D000466:Alkadienes / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D003500:Cyclization; D007192:Indenes / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D013055:Spectrophotometry, Infrared
D000143:Acids; D000466:Alkadienes; D002264:Carboxylic Acids; D007192:Indenes; D007783:Lactones; C025947:propadiene