Allenyl allylic ethers: synthesis and thermal rearrangements
摘要:
Application of the sequence halogenation/dehydrohalogenation/isomerization to alkenes 1a-g affords allenyl allylic ethers 5a-g. Thermal isomerizations of 5a,d,e proceed by Claisen rearrangement, while 5b,c,f,g are transformed by alternate modes of [2 + 2]cycloaddition involving biradical intermediates of type 19 to polycyclic structures; the variations in these thermal isomerizations are mainly a function of ring size.
Allenyl allylic ethers: synthesis and thermal rearrangements
摘要:
Application of the sequence halogenation/dehydrohalogenation/isomerization to alkenes 1a-g affords allenyl allylic ethers 5a-g. Thermal isomerizations of 5a,d,e proceed by Claisen rearrangement, while 5b,c,f,g are transformed by alternate modes of [2 + 2]cycloaddition involving biradical intermediates of type 19 to polycyclic structures; the variations in these thermal isomerizations are mainly a function of ring size.
Allenyl ethers as precursors of .alpha.-methylene-.gamma.-butyrolactones and botryodiplodin derivatives
作者:Jean Pierre Dulcere、Mohamed Naceur Mihoubi、Jean Rodriguez
DOI:10.1021/jo00073a033
日期:1993.10
Beta-Bromopropargyl ethers 2a-h, 11, and 12 or allyl propargyl ethers 8d-h are easily isomerized with potassium tert-butoxide (KO-t-Bu) into the corresponding allenyl derivatives 3a-h, 13, 14, and 9d-h. These compounds afford alpha-methylene-gamma-butyrolactones 7a-h, 25, and 26 by application of the sequence halogenation/dehydrohalogenation/homolytic carbocyclization. Starting from methyl vinyl ketone 1i, similar transformations lead to botryodiplodin (27) or ethoxybotryodiplodin (28).
Allenyl allylic ethers: synthesis and thermal rearrangements
作者:Jean Pierre Dulcere、Jack Crandall、Robert Faure、Maurice Santelli、Valerie Agati、Mohamed N. Mihoubi
DOI:10.1021/jo00073a032
日期:1993.10
Application of the sequence halogenation/dehydrohalogenation/isomerization to alkenes 1a-g affords allenyl allylic ethers 5a-g. Thermal isomerizations of 5a,d,e proceed by Claisen rearrangement, while 5b,c,f,g are transformed by alternate modes of [2 + 2]cycloaddition involving biradical intermediates of type 19 to polycyclic structures; the variations in these thermal isomerizations are mainly a function of ring size.