Facile Synthesis of 3,4-Dihydro<i>-</i>α-pyrones via Michael Reaction-O-Acylation Sequences
作者:Shû Kobayashi、Mitsuhiro Moriwaki
DOI:10.1055/s-1997-3229
日期:1997.5
3,4-Dihydro-α-pyrones were prepared in excellent yields with high stereoselectivities by the trityl salt-catalyzed Michael reaction and sequential intramolecular O-acylation of the intermediary silyl enol ethers using a mercury (II) salt (one-pot reaction).
Asymmetric Access to the Smallest Enolate Intermediate via Organocatalytic Activation of Acetic Ester
作者:Shaojin Chen、Lin Hao、Yuexia Zhang、Bhoopendra Tiwari、Yonggui Robin Chi
DOI:10.1021/ol402877n
日期:2013.11.15
An NHC-catalyzed activation of acetic esters to afford enolate intermediates is disclosed. The catalytically generated triazolium enolate intermediates serve as two-carbon nucleophiles that undergo highly enantioselective reactions with enones and alpha,beta-unsaturated imines to give a-unsubstituted delta-lactones and lactams, respectively.
Chiron,R.; Graff,Y., Bulletin de la Societe Chimique de France, 1971, p. 2145 - 2153
作者:Chiron,R.、Graff,Y.
DOI:——
日期:——
<i>N</i>-Heterocyclic Carbene Catalyzed Ring Expansion of Formylcyclopropanes: Synthesis of 3,4-Dihydro-α-pyrone Derivatives
作者:Gong-Qiang Li、Li-Xin Dai、Shu-Li You
DOI:10.1021/ol9002898
日期:2009.4.2
N-Heterocyclic carbene catalyzed ring expansion of readily accessible 2-acyl-l-formylcyclopropanes was developed. With 5 mol % of triazoliurn salt 5 and 30 mol % of DBU, ring expansion of various 2-acyl-l-formylcyclopropanes led to 3,4-dihydro-alpha-pyrones in good to excellent yields.
SHIROYAN F. R.; AVETYAN V. T., AJKAKAN KIMIAKIN AMSAGIR, ARM. XIM. ZH., 1978, 31, HO 2-3, 170-175