Showing papers on "Annulation published in 1977"
36 citations
TL;DR: In this paper, an octaline system was obtained from the reaction between 2-cyclohexenyl-1-morpholino-ethene and β-nitrostyrene, carried out under kinetic control.
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TL;DR: In this paper, the double annelation product, 2,7-dimethyl-5-silaspiro[4.4]nona-2,7diene (1), was obtained from diethoxy-, dipropoxy-, and dibutoxydichlorosilane in 87.0, 65.2, and 66.5% yields respectively.
Abstract: The in situ reaction of dialkoxydichlorosilanes, such as dimethoxy-, diethoxy-, dipropoxy-, dibutoxy-, and diisobutoxydichlorosilane, with isoprene and magnesium in tetrahydrofuran (THF) was investigated. It was found that the double annelation product, i.e., 2,7-dimethyl-5-silaspiro[4.4]nona-2,7-diene (1), was obtained from diethoxy-, dipropoxy-, and dibutoxydichlorosilane in 87.0, 65.2, and 66.5% yields respectively. On the other hand, the reaction of dimethoxy- and diethoxydichlorosilane with butadiene and magnesium in THF gave 5-silaspiro[4.4]nona-2,7-diene (7) in 20.7 and 35.4% yields respectively. Several silaspirononane derivatives were synthesized from 1.
TL;DR: The annulation of 2-amino-3-hydroxy-, 2, 5-carboxy-, 3, and 5-methyl-, 4, derivatives of the 2,3-dihydrocycloperita[d]pyrido[1,2-a]pyrimidin-10(1H) one heterocycle as mentioned in this paper gave the 5-benzyloxy derivative.
Abstract: The annulation of 2-amino-3-hydroxy-, 2-amino-3-carboxy-, and 2-amino-3-methylpyridine with ethyl cyelopenlanone-2-earboxylate led to the 5-hydroxy-, 2, 5-carboxy-, 3, and 5-methyl-, 4, derivatives of the 2,3-dihydrocycloperita[d]pyrido[1,2-a]pyrimidin-10(1H) one heterocycle. Alkylation of 2 with α-bromotolue, ne gave the 5-benzyloxy derivative.
TL;DR: In this paper, a new sequence for cyclopentenone annelation is described which involves the rearrangement of protonated bicyclic acetylcyclopropanes as a key step.
Abstract: A new sequence for cyclopentenone annelation is described which involves the rearrangement of protonated bicyclic acetylcyclopropanes as a key step. Applications of the annelation procedure to cyclohexene and cycloheptene afforded the bicyclo[4.3.0]nonane and bicyclo[5.3.0]decane frameworks, respectively. Further elaboration of the bicyclodecane derivative provides a simple and efficient synthetic route to 2-substituted azulenes.