- A diastereoselective total synthesis of trans-trikentrin A: A ring contraction approach
-
(Chemical Equation Presented) A new route to obtain the polyalkylated indole (±)-trans-trikentrin A was developed. The synthesis of this natural alkaloid features a thallium(III)-mediated ring contraction reaction to obtain the trans-1,3-disubstituted five-membered ring in a diastereoselective manner. Thallium(III) is chemoselective in this rearrangement, reacting with the olefin without oxidation of the indole moiety. Other key transformations are the Bartoli's reaction to construct the heterocyclic ring and a Heck coupling to add the carbons atom that will originate the nonaromatic cycle.
- Silva Jr., Luiz F.,Craveiro, Marcus V.
-
body text
p. 5417 - 5420
(2009/06/06)
-
- Comparative study of anionic and radical cyclization for the preparation of 1,3-dimethylindans: highly stereoselective preparation of cis-1,3-disubstituted indans via intramolecular carbolithiation.
-
[reaction: see text] The preparation of 1,3-dimethylindans from 4-(2-bromophenyl)-1-pentene (1) and 2-(2-iodo-1-methylethyl)styrene (2) substrates via radical-mediated cyclization and intramolecular carbolithiation has been investigated. Although cyclization of the radical derived from either substrate proceeds with modest selectivity for the cis-isomer, as does cycloisomerization of the aryllithium derived from substrate 1 (cis/trans approximately 2), intramolecular cyclization of the alkyllithium derived from substrate 2 is a highly cis-selective process (cis/trans = 12).
- Bailey, William F,Mealy, Michael J,Wiberg, Kenneth B
-
p. 791 - 794
(2007/10/03)
-
- Total synthesis of (±)-iso-trans-trikentrin B
-
The synthesis of the title compound, a member of a family of cyclopent[g]indoles isolated from a marine sponge, is described. Most of the synthetic sequence was developed starting from the more readily available cis-l,3-dimethylindan. An X-ray crystal structure of the indanol (24), the precursor of trns-1,3-dimethylindan, confirmed its relative stereochemistry.
- MacLeod, John K.,Ward, Annemarie,Willis, Anthony C.
-
p. 177 - 187
(2007/10/03)
-
- The Stereochemistry of Ring Closure of Some Monosubstituted o-(But-3-enyl)phenyl Radicals
-
The rates and diastereoselectivity of cyclization of o-(but-3-enyl)phenyl radicals bearing substituents on the 1- or 2-position of the side chain have been examined. 1-Substituted radicals afford only 1,5-cyclization products, but 2-substituted radicals a
- Beckwith, Athelstan L. J.,Gerba, Sendaba
-
p. 289 - 308
(2007/10/02)
-
- The Total Synthesis of (+/-)-cis- and trans-Trikentrin A
-
The synthesis of the title compounds, which are novel cyclopentindoles isolated from a marine sponge Trikentrion flabelliforme, is described.An aryl radical cyclization and a 1,5-electrocyclic reaction of a nitrene are key steps in formation of the two
- MacLeod, John K.,Monahan, Lilian C.
-
p. 329 - 337
(2007/10/02)
-
- THE SYNTHESIS OF (+/-)CIS-TRIKENTRINA
-
The synthesis of a novel sponge metabolite is described, utilising an aryl radical cyclisation to form the substituted indane system.
- Macleod, John K.,Monahan, Lilian C.
-
p. 391 - 392
(2007/10/02)
-