Finally, reductive cleavage of the cobalt complex and hydrogenation of the double bonds afforded the target (+)-cis-lauthisan 72, αD25=+4.1(c 0.9, CHCl3). Sign in to download full-size image Scheme 8. The synthesis of polycyclic ethers with variable ring sizes can be conducted by tw...
This method facilitates the construction of cis‐1,4‐silaketals (n=0, d.r.=20:1; see scheme), whereas the extension of this concept to higher alkenyl alcohols (n=1–4) results in a reversal of diastereoselectivity that favors formation of the trans isomer.P. Andrew Evans...
be run at high dilution, and does not require starting materials that include covalent conformational constraints. In addition to these needs, it is also desirable that the method yield functionalized cyclic olefins with a definite stereo-chemistry at the olefin bond; preferably, a cis conformation....
. splitting is repeatedly applied until a set of octagons is derived that cover the entire solution space, within a given precision tolerance. propagation is applied after every split, which suggests incremental closure, and a scheme in which incremental closure is applied whenever a propagator ...
describe a new approach to long-range asymmetric induction using the diastereoselective temporary silicon-tethered (TST) ring-closing-metathesis (RCM) reaction of mixed bisalkoxy silanes 1, derived from an allylic and prochiral alcohol, for the construction of cis-1,4-silaketals 2 (Scheme 1; n...
em@geus.dk; Tel.: +45-91-33-38-62 Received: 31 July 2017; Accepted: 3 October 2017; Published: 24 October 2017 Abstract: This article addresses a research gap on the challenges—specifically risk and value—connected to realizing the potential for closing loops for rare earth elements (REE...