Preparation of the A-ring of neocarzinostatin and kedarcidin chromophores via a stereocontrolled base mediated isomerisation reaction
作者:Stephen Caddick、Safraz Khan
DOI:10.1039/c39950001971
日期:——
A new base promoted isomerisation of 6-(1,1-dimethylethoxy)-2H-pyran-3-one to 4-(1,1-dimethylethoxy)-5-hydroxy-2-cyclopentenone is used in the preparation of 2-bromo-5-[(1,1-dimethylethyl)dimethylsilyloxy]-4-hydroxy-2-cyclopentenone, a potential intermediate for use in the synthesis of Neocarzinostatin and Kedarcidin chromophores.
Improved procedure for the synthesis of 6-alkoxy-2,3-dihydro-6h-pyran-3-ones (2,3-dideoxy-dl-pent-2-enopyranos-4-uloses). Neat conversion into polyfunctionalized cyclopentenones
作者:Bernd Mucha、H. Martin、R. Hoffmann
DOI:10.1016/s0040-4039(01)80725-5
日期:1989.1
A ring contraction of 6-alkoxy-2,3-dihydro-6h-pyran-3-ones to polyfunctionalized cyclopentenones
作者:Hartmuth C. Kolb、H.Martin R. Hoffmann
DOI:10.1016/s0040-4020(01)87820-0
日期:1990.1
MUCHA, BERND;HOFFMANN, M. MARTIN R., TETRAHEDRON LETT., 30,(1989) N4, C. 4489-4492
作者:MUCHA, BERND、HOFFMANN, M. MARTIN R.
DOI:——
日期:——
Asymmetric synthesis of trans-4,5-dioxygenated cyclopentenone derivatives by organocatalyzed rearrangement of pyranones and enzymatic dynamic kinetic resolution
作者:João P.M. Nunes、Luís F. Veiros、Pedro D. Vaz、Carlos A.M. Afonso、Stephen Caddick
DOI:10.1016/j.tet.2011.02.018
日期:2011.4
Dioxygenated cyclopentenones are versatile building blocks for the synthesis of several natural products. Herein we report a direct asymmetric synthesis of trans-4,5-dioxygenated cyclopentenone derivatives through base-catalyzed rearrangement of pyranones followed by dynamic kinetic resolution. Milder conditions than previously reported for this rearrangement have been found regarding amine base catalysis