81036-90-0Relevant academic research and scientific papers
One-pot construction of multi-substituted spiro-cycloalkanediones by an organocatalytic asymmetric epoxidation/semipinacol rearrangement
Li, Bao-Sheng,Zhang, En,Zhang, Qing-Wei,Zhang, Fu-Min,Tu, Yong-Qiang,Cao, Xiao-Ping
experimental part, p. 2269 - 2272 (2012/06/30)
A one-pot preparation of chiral tri-oxygenated spirocycloalkanediones with up to 99 % ee features high stereoselectivity, the introduction of tri-oxygenated functional groups, and the efficient construction of at least two chiral centers. Copyright
Ketalised α- and β-lithiated α,β-unsaturated ketones: New masked acylvinyl anion equivalents
Bachki, Abderrazak,Foubelo, Francisco,Yus, Miguel
, p. 4921 - 4934 (2007/10/03)
The reaction of chloroketals 1, 5 and 10 with an excess of lithium powder and a catalytic amount of DTBB (4-5%) in THF at -78 or -90°C leads to the corresponding functionalised organolithium compounds 2, 6 and 11, respectively, resulting from a chlorine/l
Use of Protected β-Bromocyclopentenones and β-Bromocyclohexenones as β-Acylvinyl Anion Equivalents
Shih, Chuan,Swenton, John S.
, p. 2825 - 2832 (2007/10/02)
Ethylene glycol ketals of the 3-bromocyclohex-2-en-1-one as well as its 2-methyl, 2-n-propyl, and 5,5-dimethyl derivatives have been prepared, and their reactions with butyllithium were studied.The organolithium reagents derived from the above compounds react with a variety of electrophiles to afford after acid hydrolysis the corresponding 3-substituted cyclohexenones.Attempts to prepare the ethylene glycol ketal of 2-methyl-3-bromocyclopent-2-en-1-one gave a low yield of the bromoketal.However, dithioketals of 3-bromocyclopent-2-en-1-one and its 2-methyl derivativecould be prepared in good yield.The metalation chemistry of the dithioketals in both the five- and six-membered-ring series was examined.The functionalization chemistry of the resulting organolithium compounds afforded after dithioketal hydrolysis 3-functionalized cyclohex-2-en-1-ones and cyclopent-2-en-1-ones.Several limitations of the chemistry using allyl bromide and cyclohexenone as electrophiles are noted.
An Efficient and Simple β-Acylvinyl Anion Equivalent for Cyclohexenones
Shih, Chuan,Swenton, John S.
, p. 4217 - 4220 (2007/10/02)
Dilithio species available from treatment of Δ3,4-3-bromocyclohexenone ketals with two equivalents of n-butyllithium serve as one-pot equivalents of β-vinyl-carbanions of cyclohexenones.These former ketals are available in good yield from the corresponding β-bromocyclohexenone by direct ketalization under controlled conditions.
