Total Synthesis, Relay Synthesis, and Structural Confirmation of the C18-Norditerpenoid Alkaloid Neofinaconitine
作者:Yuan Shi、Jeremy T. Wilmot、Lars Ulrik Nordstrøm、Derek S. Tan、David Y. Gin
DOI:10.1021/ja4064958
日期:2013.9.25
skeleton 33 of the aconitine alkaloids. Key endgame transformations include the installation of the C8-hydroxyl group via conjugate addition of water to a putative strained bridghead enone intermediate 45 and one-carbon oxidative truncation of the C4 side chain to afford racemic neofinaconitine. Complete structural confirmation was provided by a concise relay synthesis of (+)-neofinaconitine and (+)-9-deoxylappaconitine
1,2,2-tribromocyclopropanecarboxylic acid and derivatives—Valuable intermediates for four carbon cyclopropane and cyclopropene synthons
作者:Ahmad R. Al Dulayymi、Juma'a R. Al Dulayymi、Mark S. Baird、Michelle E. Gerrard、Gani Koza、Samantha D. Harkins、Evan Roberts
DOI:10.1016/0040-4020(95)01123-4
日期:1996.3
2-bromocyclopropene carboxylate. while modification of the ester group followed by reaction with methyllithium leads to a series of related four-carbon cyclopropenes. The tribromo-ester is also readily converted into 1,1,2,2-tetrabromocyclopropane, a valuable three-carbon cyclopropene synthon.
作者:Ahmad R. Al Dulayymi、Juma'a R. Al Dulayymi、Mark S. Baird
DOI:10.1016/s0040-4020(99)01069-8
日期:2000.2
or t-butyllithium leads to a 1,3-dehalogenation to produce [4.1.1]propellanes. The oxygen bridgedpropellane derived from furan reacts with a second mole equivalent of n-butyllithium by cleavage of the bridge with allylic rearrangement and the formation of a cis-2-butyl[4.1.1]propell-3-en-1-ol. Iodination of this leads to rearrangement with the production of 6-methylene-8-oxabicyclo[3.2.1]oct-2-enes