An Improved Method for the Syntheses of β-Substituted Cyclohexenones
摘要:
An improved method for the preparation of beta-substituted cyclohexenones is reported. Conditions were defined to effectuate the key desulfonylation-deketalization step in a mild manner. Several cyclohexenones bearing acid and/or base sensitive beta-substituents were prepared by the modified method in moderate to good yields.
Preparation and reactivity of functionalized alkenyl-zinc, -copper, and -chromium organometallics
作者:Paul Knochel、C. Janakiram Rao
DOI:10.1016/s0040-4020(01)80504-4
日期:1993.1
Beta-halogeno-alpha,beta-unsaturated carbonyl derivatives were converted to the corresponding zinc organometallics 2a under mild conditions in THF (Zn dust, 25-45-degrees-C, 1-4h). These functionalized alkenylzinc iodides react with a variety of alkenyl and aromatic iodides affording the desired coupling products in 40-97% yield. The addition of a THF solution of CuCN.2LiCl to 2a affords the corresponding organocopper derivatives 2b which react with electrophiles, such as alkynyl and allylic halides, nitro olefins, enones, and chlorotrimethylstannane providing polyfunctional unsaturated carbonyl compounds in 71-95% yield. The insertion of chromium (II) chloride to beta-iodo and to some beta-(p-tosyl)enones in DMF furnishes new functionalized chromium (III) organometallics 2c which react with aldehydes providing gamma-hydroxy unsaturated carbonyl derivatives in 40-91% yield. The synthetic scope and the limitations of this methodology are discussed.
Use of protected .beta.-bromocyclopentenones and .beta.-bromocyclohexenones as .beta.-acylvinyl anion equivalents
作者:Chuan Shih、John S. Swenton
DOI:10.1021/jo00136a001
日期:1982.7
An efficient and simple β-acylvinyl anion equivalent for cyclohexenones
作者:Chuan Shih、John S. Swenton
DOI:10.1016/s0040-4039(01)82108-0
日期:——
New methods for β-conjugate addition and β-hydroxyalkylation of enones
作者:Sunggak Kim、Phil Ho Lee
DOI:10.1016/s0040-4039(00)82882-8
日期:——
Jin, Zhendong; Fuchs, Journal of the American Chemical Society, 1994, vol. 116, # 13, p. 5995 - 5996