Studies Directed toward the Total Synthesis of Azaspiracid: Stereoselective Construction of C<sub>1</sub>−C<sub>12</sub>, C<sub>13</sub>−C<sub>19</sub>, and C<sub>21</sub>−C<sub>25</sub> Fragments
作者:Rich G. Carter、David J. Weldon
DOI:10.1021/ol006674w
日期:2000.11.1
[reaction: see text] The efficient entry to the C(1)-C(12), C(13)-C(19), and C(21)-C(25) fragments of azaspiracid is outlined. The C(1)-C(12) portion is constructed using a key asymmetric allenyl borane addition to the corresponding alpha,beta-unsaturated aldehyde. The synthesis of the C(13)-C(19) portion utilizes an Evans asymmetric alkylation followed by Sharpless asymmetric dihydroxylation. In addition
作者:Steven V. Ley、Miles N. Tackett、Matthew L. Maddess、James C. Anderson、Paul E. Brennan、Michael W. Cappi、Jag P. Heer、Céline Helgen、Masakuni Kori、Cyrille Kouklovsky、Stephen P. Marsden、Joanne Norman、David P. Osborn、María Á. Palomero、John B. J. Pavey、Catherine Pinel、Lesley A. Robinson、Jürgen Schnaubelt、James S. Scott、Christopher D. Spilling、Hidenori Watanabe、Kieron E. Wesson、Michael C. Willis
DOI:10.1002/chem.200801656
日期:2009.3.9
Rapamycin (1) is a macrocyclic natural product, established as a potent immunosuppressant and currently of interest to the scientific community as the framework for a series of novel anticancer drugs. Extensive studies have culminated in a new convergent totalsynthesis of 1, which features a number of group‐derived methodologies and an unusual catechol‐templating strategy for the construction of the
Die Titelverbindung 1 wurde über 15 Stufen mit 0.5% Gesamtausbeute aus meso-2,4-Dimethylglutarsäureanhydrid (17) hergestellt. Der erste Teil der Synthese folgte dabei der Prelog-Djerassi-Lacton-Synthese von Bartlett, außer daß eines der Zwischenprodukte durch enzymatische Hydrolyse eines achiralen meso-Diesters in optischaktiver Form (ca. 77% ee) hergestellt wurde. Besondere Schwierigkeiten bereitete
(–)-Probetaenone I (1) has been synthesized by an intramolecular Diels–Alder reaction and, thereby, its structure has been clearly confirmed; in the biosynthesis of betaenoneB (2) the stereochemistry of the C-8 hydroxylation of (1) was proved to involve retention of configuration.