16149-89-6Relevant articles and documents
Hydroxylamine catalyzed Nazarov cyclizations of divinyl ketones Dedicated to Professor Hilton Weiss on his 80th birthday
Hamilton, Joseph Z.,Kadunce, Nathaniel T.,McDonald, Michael D.,Rios, Laura,Matlin, Albert R.
, p. 6622 - 6624 (2015)
The first examples of iminium catalyzed Nazarov cyclizations of divinyl ketones are presented. Experiments describing hydroxylamine catalysis of the cyclization of eight α-alkoxy divinyl ketones (60-79% yield) and one unactivated divinyl ketone (38% yield) are reported. Phenyl substitution at the β-position of the divinyl ketone inhibits cyclization, whereas β-alkyl substituted α-alkoxy divinyl ketones readily cyclize.
Synthesis of spiro[4.5]decane and bicyclo[4.3.0]nonane ring systems by self-cyclization of (Z)- and (E)-2-(trimethylsilylmethyl)pentadienal derivative
Kuroda, Chiaki,Honda, Shigenobu,Nagura, Yuki,Koshio, Hiroyuki,Shibue, Taku,Takeshita, Tokio
, p. 319 - 331 (2007/10/03)
The two title carbon frameworks were synthesized utilizing a new type of iron-induced cyclization reaction of 2-(trimethylsilylmethyl)pentadienal. 2-Methylspiro[4.5]dec-2-en-1-one was obtained from (Z)- and (E)-4- cyclohexylidene-2-(trimethylsilylmethyl)but-2-enal. It was found that the (Z)-substrate isomerized to (E)-intermediate followed by cyclization to afford the initial product, 2-methylenespiro[4.5]dec-3-en-1-ol, which was isomerized to the above product. The cyclization of 4-(4-alkyl)cyclohexylidene-2- (trimethylsilylmethyl)but-2-enal proceeded stereoselectively. While, (E)-3-(cyclohex-1-en-1-yl)-2-(trimethylsilylmethyl)prop-2-en-1-al cyclized immediately affording 8-methylenebicyclo[4.3.0]non-9-en-7-ol. The corresponding (Z)-isomer gave several cyclization products as a complex mixture.
