1,3-Cyclobutanediones (dialkyl ketene dimer) reacted with various aromatic aldehydes to give six-membered cyclic β-keto esters by using a catalytic amount of potassium ethoxide. Effects of alkoxide catalysts and spiro cyclic groups at the 2,4-positions of 1,3-cyclobutanediones were investigated.
The photochemicalringexpansion of dispirosubstitutedcyclobutane-1,3-diones in methanol has been investigated. The formation of ringexpansion product was strongly dependent on the spiro ring size of dispiro substituent. The ring expanded acetal was obtained in a low yield when the spiro ring of dispirosubstitutedcyclobutane-1,3-diones was a five- or seven-membered ring. This is the first example
The synthesis, structure, conformation, and dynamics of a new rotane family consisting of four-membered rings are described. All syntheses are based on bicyclobutylidene (9): [2+1] cycloaddition of cyclobutylidene yields [3.4]rotane (5) (9−5), [2+2] cycloaddition of trimethyleneketene followed by spiroalkylation of the resulting trispiroketone 10 yields [4.4]rotane (6) (9−10−13−14−6), homologization
The reaction of 2,2,4,4-tetramethyl-1,3-cyclobutanedione with<i>o</i>-aminophenols,<i>o</i>-aminothiophenol and with aliphatic 2- and 3-hydroxy- and -mercaptoamines
作者:Siegfried Linke
DOI:10.1002/jhet.5570100507
日期:1973.10
Studies of the reaction of the dione dimer of dimethylketene (1) with a series of o-aminophenols and with o-aminothiophenol have been carried out. These reactions give 2-[2-(2,4-dimethyl-3-oxopentyl)]benzoxazoles and -benzothiazole, respectively. Aliphatic 2- and 3-hydroxy- and 2- and 3-mercaptoamines yield 2-substituted 2-oxazolines, 5,6-dihydro-4H-1,3-oxazines, 2-thiazolines and 5,6-dihydro-4H-1
已经进行了二甲基乙烯酮(1)的二酮二聚体与一系列邻氨基苯酚和邻氨基硫基苯酚的反应的研究。这些反应分别得到2- [2-(2,4-二甲基-3-氧戊基)]苯并恶唑和-苯并噻唑。脂肪族的2-和3-羟基-和2-和3-巯基胺产生2-取代的2-恶唑啉,5,6-二氢-4 H -1,3-恶嗪,2-噻唑啉和5,6-二氢-4 H -1,3-噻嗪。
Photochemistry of dispiro-1,3-cyclobutanediones in methylene chloride and methanol solutions