High Regio-, Chemo-, and Stereoselectivity via Low-Temperature 4 + 3 Cycloadditions. Convergent Synthesis of Multifunctionalized Vinylmetals (M = Si, Sn) and S-Vinyl Benzenecarbothioates
摘要:
[GRAPHICS]A series of enantiomerically pure 8-oxabicyclo[3.2.1]oct-6-en-3-ones functionalized in the unsaturated two-carbon bridge has been prepared by the title reaction. Carbocation reactivity has been fined-tuned at -95 degrees C and adjusted to diene nucleophilicity. Conventional electrophilic substitution of 3-silylated and 3-stannylated furan is suppressed in favor of the rapid 4 + 3 cycloaddition mode. In the case of cycloadduct 13A, stereoselectivity (17:1) is perfectly matched to regioselectivity (17:1). High stereoselection as well as unprecedented regioselection and chemoselection is attributed to the low-temperature cycloaddition protocol and the design of chiral auxiliary and tether.
High Regio-, Chemo-, and Stereoselectivity via Low-Temperature 4 + 3 Cycloadditions. Convergent Synthesis of Multifunctionalized Vinylmetals (M = Si, Sn) and S-Vinyl Benzenecarbothioates
摘要:
[GRAPHICS]A series of enantiomerically pure 8-oxabicyclo[3.2.1]oct-6-en-3-ones functionalized in the unsaturated two-carbon bridge has been prepared by the title reaction. Carbocation reactivity has been fined-tuned at -95 degrees C and adjusted to diene nucleophilicity. Conventional electrophilic substitution of 3-silylated and 3-stannylated furan is suppressed in favor of the rapid 4 + 3 cycloaddition mode. In the case of cycloadduct 13A, stereoselectivity (17:1) is perfectly matched to regioselectivity (17:1). High stereoselection as well as unprecedented regioselection and chemoselection is attributed to the low-temperature cycloaddition protocol and the design of chiral auxiliary and tether.
作者:Joseph Benford‐Ward、Sanaz Ahmadipour、Aliya Sembayeva、Louise Male、Richard S. Grainger
DOI:10.1002/chem.202202429
日期:2022.12.20
Hajos-Parrish ketone is used to prepare a key building block for the total synthesis of the marine natural product dictyoxetane in enantiopure form. A synthetic alternative to the Garst-Spencer furan annelation is developed, and the reactivity and diastereoselectivity of the resulting tetrasubstituted chiral furan in cycloaddition reactions towards an appropriately functionalised carbocyclic core of dictyoxetane
Stark, Christian B. W.; Pierau, Sabine; Wartchow, Rudolf, Chemistry - A European Journal, 2000, vol. 6, # 4, p. 684 - 691
作者:Stark, Christian B. W.、Pierau, Sabine、Wartchow, Rudolf、Hoffmann
DOI:——
日期:——
High Regio-, Chemo-, and Stereoselectivity via Low-Temperature 4 + 3 Cycloadditions. Convergent Synthesis of Multifunctionalized Vinylmetals (M = Si, Sn) and <i>S</i>-Vinyl Benzenecarbothioates
作者:Hartmut Beck、Christian B. W. Stark、H. Martin R. Hoffmann
DOI:10.1021/ol991386p
日期:2000.4.1
[GRAPHICS]A series of enantiomerically pure 8-oxabicyclo[3.2.1]oct-6-en-3-ones functionalized in the unsaturated two-carbon bridge has been prepared by the title reaction. Carbocation reactivity has been fined-tuned at -95 degrees C and adjusted to diene nucleophilicity. Conventional electrophilic substitution of 3-silylated and 3-stannylated furan is suppressed in favor of the rapid 4 + 3 cycloaddition mode. In the case of cycloadduct 13A, stereoselectivity (17:1) is perfectly matched to regioselectivity (17:1). High stereoselection as well as unprecedented regioselection and chemoselection is attributed to the low-temperature cycloaddition protocol and the design of chiral auxiliary and tether.