150919-19-0Relevant articles and documents
Studies on Mercury(II)-Mediated Opening of Bi- and Tercyclopropane Arrays
Barrett, Anthony G. M.,Tam, William
, p. 4653 - 4664 (1997)
The first examples of the mercury(II)-mediated ring opening of bicyclopropane and tercyclopropane arrays have been investigated. The presence of an adjacent cyclopropyl group dramatically increased the rate of the mercury-mediated opening of the first cyclopropane in a cyclopropane array. In contrast to the mercury-mediated ring opening of monocyclopropanes which usually undergo a concerted ring-opening mechanism, electrophilic openings of cyclopropane arrays occurred through a stabilized, free carbocation. Excellent regio- and stereoselectivities were observed in the mercury- mediated intramolecular openings of the second cyclopropanes in the cyclopropane arrays, giving rise to the formation of enantiomerically pure, highly substituted tetrahydrofurans.
An efficient synthesis of dienic nucleoside analogues via a Mitsunobu reaction
Hubert, Cécile,Alexandre, Christian,Aubertin, Anne-Marie,Huet, Fran?ois
, p. 3127 - 3130 (2007/10/03)
Nucleoside analogues 9 and 12 were obtained in good yields from alcohol 7 which, under Mitsunobu conditions, led to the title products after deprotection steps.
Total synthesis of an antitumor antibiotic, fostriecin (CI-920)
Miyashita, Kazuyuki,Ikejiri, Masahiro,Kawasaki, Hitomi,Maemura, Satoko,Imanishi, Takeshi
, p. 8238 - 8243 (2007/10/03)
The total synthesis of an antitumor antibiotic, fostriecin (CI-920), via a highly convergent route is described. A characteristic feature of the present total synthesis is that the synthesis was achieved via a coupling procedure of three segments A, B, an
The preparation and electrocyclic ring-opening of cyclobutenes: Stereocontrolled approaches to substituted conjugated dienes and trienes
Binns, Falmai,Hayes, Roy,Hodgetts, Kevin J.,Saengchantara, Suthiweth T.,Wallace, Timothy W.,Wallis, Christopher J.
, p. 3631 - 3658 (2007/10/03)
Thermal electrocyclic ring-opening of 4-alkyl-2-cyclobutene-1-carbaldehydes occurs at low temperature to give (2Z,4E)-alkadienals exclusively, and the process is exploited in transforming cis-3-cyclobutene-1,2-dimethanol 1 into a variety of naturally occurring 1,3,5-alkatrienes and 2,4-decadienoates. Desymmetrisation of 1 with Pseudomonas fluorescens lipase gives access to both enantiomers of 3-oxabicyclo[3.2.0]hept-6-en-2-one 4, for use in stereocontrolled routes to 6-oxygenated (2Z,4E)-alkadienals.
Asymmetric synthesis of bicyclopropane derivatives
Barrett, Anthony G. M.,Doubleday, Wendel W.,Tustin, Gary J.
, p. 15325 - 15338 (2007/10/03)
Both syn- and anti-bicyclopropane derivatives have been efficiently prepared with good relative and absolute stereocontrol using reagent controlled asymmetric cyclopropanation reactions. Double Simmons-Smith cyclopropanation of 2,4-dien-1-ols stereoselectively gave the corresponding anti-bicyclopropane derivatives.
Studies towards the Synthesis of FR-900848: Stereoselective Preparation of anti-Bicyclopropane Derivatives
Barrett, Anthony G. M.,Tustin, Gary J.
, p. 355 - 356 (2007/10/02)
Double Simmons-Smith cyclopropanation of 2,4-dien-1-ols stereoselectively gives the corresponding anti-bicyclopropane derivatives.
Use of cis-3-cyclobutene-1,2-dimethanol in stereoselective routes to some naturally occurring conjugated dienes and trienes
Hodgetts, Kevin J.,Saengchantara, Suthiweth T.,Wallis, Christopher J.,Wallace, Timothy W.
, p. 6321 - 6324 (2007/10/02)
Thermal electronic ring-opening of 4-alkyl-2-cyclobutene-1-carbaldehydes occurs at low temperature to give (2Z,4E)-alka-2,4-dienals exclusively, and this process is exploited en route to various isomeric naturally occurring 1,3,5-alkatrienes and 2,4-decadienoates from a single precursor, cis-3-cyclobutene-1,2-dimethanol 4.
Transannular Diels-Alder reactions on 14-membered macrocyclic trienes. Part I: stereoselective syntheses of the macrocyclic trienes precursors
Ndibwami, Alexis,Lamothe, Serge,Guay, Daniel,Plante, Raymond,Soucy, Pierre,et al.
, p. 695 - 713 (2007/10/02)
Transannular Diels-Alder reactions on 14-membered macrocycles containing properly located diene and methyl-substituted dienophile units lead to A.B.C. tricycles related to steroids.To study the influence of the olefin and diene geometry on the stereochemical outcome of the Diels-Alder reaction it was necessary to prepare macrocyclic trienes of well-defined stereochemistry.Eight different types of macrocyclic trienes might be obtained by the coupling of appropriate dienophiles and dienes, namely, TTC, TTT, TCC, TCT, CTC, CTT, CCC, and CCT.In this paper (first in a series of two), the synthesis of appropriately functionalized dienophile and diene synthons, as well as their coupling reaction affording macrocyclic triene precursors, is described.
Synthesis and transannular Diels-Alder reaction of a 13-membered macrocyclic triene. A synthetic approach towards the tricyclic part A.B.C.[6.6.5] of the veratrum alkaloids
Quimpere,Ruest,Deslongchamps
, p. 132 - 140 (2007/10/02)
The syntheses of the acyclic triene cis-trans-trans (3Z,9Z,11E)-13-chloro-3-methoxy-1,1,7,7-tetrakis(methoxycarbonyl)-4- methyltrideca-3,9,11-triene (25), and the corresponding trans-cis-trans (3Z,9E,11E) isomer 37, and trans-trans-trans (3Z,9E,11E) isomer, 46, are described. Compounds 25 and 37 furnished in good yield 13-membered macrocyclic compounds (3Z,9Z,11E)- and (3Z,9E,11Z)-3-methoxy-1,1,7,7-tetrakis(methoxycarbonyl)-4- methylcyclotride-ca-3,9,11-triene (26) and (38) which led to tricyclic compound (cis-anti-cis)-2-methoxy-4,4,11,11-tetrakis(methoxycarbonyl)-1- methyl-tricyclo[7.4.0.02,6]tridec-7-ene (27) by transannular Diels-Alder reaction. Macrocyclization of trans-trans-trans chloride 46 was not successful.
