Construction of Carbo- and Heterocycles Using Radical Relay Cyclizations Initiated by Alkoxy Radicals
作者:Hai Zhu、Jason G. Wickenden、Natalie E. Campbell、Joe C. T. Leung、Kayli M. Johnson、Glenn M. Sammis
DOI:10.1021/ol900481e
日期:2009.5.7
construction of carbo- and heterocycles has been developed using radical relay cyclizations initiated by alkoxy radicals. Linear substrates were cyclized to form a wide range of cyclopentane, pyrrolidine, tetrahydropyran, and tetrahydrofuran derivatives in excellent yields. This methodology was utilized as a key step in the synthesis of the tetrahydrofuran fragment in (−)-amphidinolide K.
Stereocontrolled synthesis of the C-1 to C-7 fragment of erythronolide A. A model study using the 1,7-dioxaspiro[5.5]undecane system
作者:Gilles Sauvé、David A. Schwartz、Luc Ruest、Pierre Deslongchamps
DOI:10.1139/v84-496
日期:1984.12.1
A partir de l'oxo-3 heptene-6oate de methyle, synthese du propionate de dioxa-1,7spiro [5.5] undecene-2methanol-3; ce compose est ensuite transforme en benzyloxy-3 α,γ-dimethyl β-hydroxy methyl-3 dioxa-1,7spiro [5.5] undecanebutyrate-2 de methyle possedant les 5 centres chiraux contigus que l'on retrouve dans l'acide seco de l'erythronolide A
a partir de l'oxo-3 heptene-6oate demethyle,合成 du propionate de dioxa-1,7spiro [5.5] undecene-2methanol-3;ce compose est ensuite transforme en benzyloxy-3 α,γ-dimethyl β-hydroxymethyl-3 dioxa-1,7spiro [5.5] undecanebutyrate-2 demethyle possedant les 5 centre chiraux contigus que l'on retrouve dans l'acide seco de L'erythronolide A
Lewis Base Catalyzed, Sulfenium Ion Initiated Enantioselective, Spiroketalization Cascade
作者:Kimberly M. Hilby、Scott E. Denmark
DOI:10.1021/acs.joc.1c02271
日期:2021.11.5
A Lewisbasecatalyzed, enantioselective sulfenocyclization of alkenes to afford [6,6]spiroketals has been developed. The method uses a chiralLewisbase catalyst with an electrophilic sulfur source to generate enantioenriched thiiranium ion with alkenes. Upon formation, the thiiranium ion is subsequently captured in a cascade-type reaction, wherein a ketone oxygen serves as the nucleophile to open
A first total synthesis of broussonetine F from diethyl l-tartrate was achieved. The cornerstone of our synthesis was an orthoamide Overmanrearrangement, which provided an allylic amino alcohol with complete diastereoselectivity.