68241-78-1Relevant articles and documents
Small-scale procedure for acid-catalyzed ketal formation
Wright, Austin C.,Du, Yun Emily,Stoltz, Brian M.
, p. 11258 - 11260 (2019)
A modified procedure for dehydrative ketal protections is disclosed, which serves as an alternative to the classic Dean-Stark protocol. Studies show that this new procedure can outperform the Dean-Stark apparatus on small scales and thus serves as a complementary approach to effect dehydrative ketalizations. A detailed procedure for this apparatus is presented.
Synthesis of ACE tricyclic systems of daphnicyclidin A and dehy-droxymacropodumine A
Wang, Qi,Zhang, Chao,Yang, Jun
supporting information, p. 1906 - 1910 (2019/12/27)
The synthesis of the ACE tricyclic system of daphnicyclidin A and dehydroxymacropodumine A are developed. The key reactions include an efficient aldol reaction to introduce chiral fragment 33 for further construction of piperidine ring B and seven-membered ring C, a nucleophilic addition of lithium pentene to aldehyde for installation of ring E, and a photocatalytic decarboxylation conjugate addition to construct ring C.
Enantioselective construction of the tricyclic core of curcusones A-D: Via a cross-electrophile coupling approach
Wright, Austin C.,Stoltz, Brian M.
, p. 10562 - 10565 (2019/12/02)
Herein we report our recent progress toward the enantioselective total synthesis of the diterpenoid natural products curcusones A-D by means of complementary Stetter annulation or ring-closing metathesis (RCM) disconnections. Using the latter approach, we
Five- and six-membered cyclic α-acylvinyl anionic synthons: Synthesis of α-trimethylsilyl-α,β-unsaturated cycloalkenones and their conversion into 2-(hydroxydimethylsilyl)cycloalk-2-enones through carbon-silicon bond scission
Jyothi, Divya,Suresh, Hariprasad
experimental part, p. 194 - 203 (2012/05/20)
Five- and six-membered α-trimethylsilyl-α,β-unsaturated cycloalkenones were prepared by the Wurtz-Fittig coupling reaction of the corresponding 6-bromo-1,4-dioxaspiro[4,n]cycloalk-6-enes with sodium and chlorotrimethylsilane. Upon treatment with anhydrous
Synthesis and stereochemical confirmation of the secoiridoid glucosides nudiflosides D and A
Hanessian, Stephen,Mainetti, Emily,Lecomte, Fabien
, p. 4047 - 4049 (2007/10/03)
We describe herein an efficient access to the highly substituted cyclopentane unit present in the Nudifloside secoiridoid family via crotyl phosphonamide anion mediated conjugate addition to cyclopentenone.
A Convenient Procedure for the Synthesis of Acetals from α-Halo Ketones
Carlson, Rolf,Gautun, Hanna,Westerlund, Andreas
, p. 57 - 60 (2007/10/03)
A study for determining the scope and limitations of a procedure for synthesising ethylene acetals from haloketones is presented. The method uses 1,2-bis(trimethylsilyloxy)ethane, BTSE, as reagent and Nafion-TMS as catalyst. Two procedures have been tested: (A) stoichiometric amounts of the haloketone and BTSE and a catalytic amount of Nafion-TMS were heated to reflux in chloro-form solution, and (B) stoichiometric amounts of the reactants and a catalytic amount of Nafion-TMS were heated to 90-100°C in the absence of solvent. The following ketones have been tested: 2-bromo-1-phenyl-1-ethanone, 2-bromo-cyclopentenone, 3-bromo-3-methyl-2-butanone, 3-chloro-3-methyl-2-butanone, 1-bromo-3,3-dimethyl-2-butanone, 1-chloro-3,3-dimethyl-2-butanone, 2-bromocyclohexanone, 2-chloro-1-cyclohexyl-1-ethanone, 1,1-dibromo-3,3-dimethyl-2-butanone, 1,3-dibromo-3-methyl-2-butanone, 1,3-dibromo-2-butanone, 1,3-dibromo-2-propanone, 2-chloro-1-phenyl-1-ethanone, and endo-2-bromocamphor. Yields were in the range 57-100% with the exceptions of endo-2-bromocamphor which afforded 10% yield and the dibromoketones 1,1-dibromo-3,3-dimethyl-2-butanone and 1,3-dibromo-3-methyl-2-butanone for which the method failed. Factors determining the scope and limitations are briefly discussed. Full experimental details and spectroscopic data of the acetals are given.
Palladium-catalyzed trimerization of strained cycloalkynes: Synthesis of decacyclene
Iglesias, Beatriz,Pe?a, Diego,Pérez, Dolores,Guitián, Enrique,Castedo, Luis
, p. 486 - 488 (2007/10/03)
Palladium-catalyzed cyclotrimerization was applied to three strained cycloalkynes. Pd(PPh3)4 and Pt(PPh3)4-catalyzed cyclotrimerizations of cyclohexyne (2) afforded dodecahydrotriphenylene (3) in 64% and 62% yields, respectively, but subjecting cyclopentyne to the same conditions failed to afford isolable amounts of the cyclotrimer. Finally, decacyclene (15), a putative C60-fullerene precursor, was obtained in 23% yield by Pd2(dba)3-catalyzed cyclotrimerization of acenaphthyne (14).
Highly Selective Methods for α-Alkenylation and α-Arylation of Ketones via Palladium- or Nickel-Catalyzed Cross Coupling
Negishi, Ei-ichi,Akiyoshi, Kazunari
, p. 1007 - 1010 (2007/10/02)
Two procedures for α-alkenylation and α-arylation of ketones, that permit, for the first time, introduction of a stereo-defined alkenyl group (E or Z) in the α-position of cyclic ketones in high yields with essentially complete retention (>98percent) of the alkenyl stereochemistry are reported.Furthermore, the one that is represented by Eq.2 permits complete control of regiochemistry as well.
