573699-05-5Relevant articles and documents
BIMP-Catalyzed 1,3-Prototropic Shift for the Highly Enantioselective Synthesis of Conjugated Cyclohexenones
Carter, Eve M.,Dixon, Darren J.,Golec, Jonathan C.,Paton, Robert S.,Simón, Luis,Ward, John W.,Whittingham, William G.
supporting information, p. 17417 - 17422 (2020/08/10)
A bifunctional iminophosphorane (BIMP)-catalysed enantioselective synthesis of α,β-unsaturated cyclohexenones through a facially selective 1,3-prototropic shift of β,γ-unsaturated prochiral isomers, under mild reaction conditions and in short reaction times, on a range of structurally diverse substrates, is reported. α,β-Unsaturated cyclohexenone products primed for downstream derivatisation were obtained in high yields (up to 99 %) and consistently high enantioselectivity (up to 99 % ee). Computational studies into the reaction mechanism and origins of enantioselectivity, including multivariate linear regression of TS energy, were carried out and the obtained data were found to be in good agreement with experimental findings.
Tremorgenic Indole Alkaloids. 9. Asymmetric Construction of an Advanced F-G-H-Ring Lactone Precursor for the Synthesis of Penitrem D
Smith, Amos B.,Nolen, Ernest G.,Shirai, Ryuichi,Blase, Frances R.,Ohta, Mitsuaki,et al.
, p. 7837 - 7848 (2007/10/03)
Lactone (+)-12 is envisioned as the precursor to the F-G-H rings of penitrem D (4) in our ongoing synthetic venture.The efficient, stereocontrolled introduction of the vicinal quaternary methyl groups present the major challenge in the construction of this subunit.Our first route to (+/-)-12 was marked by low overall yield (2percent) and the instability of several key intermediates; these deficiencies were rectified in a second-generation approach that produced optically active material (18 steps from 19a, 2.1percent overall).The successful strategies exploited enolate generation via either conjugate additions to α,β-enones or the Evans oxy-Cope rearrangement as key regiochemical control elements.
