A temporary stereocentre approach for the asymmetric synthesis of chiral cyclopropane-carboxaldehydes
作者:Matt Cheeseman、Iwan R. Davies、Phil Axe、Andrew L. Johnson、Steven D. Bull
DOI:10.1039/b908600e
日期:——
A novel way of combining chiral auxiliaries and substrate directable reactions is described that employs a three-step sequence of aldol/cyclopropanation/retro-aldol reactions for the asymmetric synthesis of enantiopure cyclopropane-carboxaldehydes. In the first step, reaction of the boron enolate of (S)-N-propionyl-5,5-dimethyl-oxazolidin-2-one with a series of α,β-unsaturated aldehydes affords their
A novel strategy for the asymmetric synthesis of chiral cyclopropane carboxaldehydes
作者:Matt Cheeseman、Fred J. P. Feuillet、Andrew L. Johnson、Steven D. Bull
DOI:10.1039/b501847a
日期:——
A new way of combining chiral auxiliaries and substrate-directable reactions for asymmetricsynthesis is described that employs a three-step sequence of aldol-cyclopropanation-retro-aldol reactions for the stereoselective synthesis of enantiopure cyclopropane carboxaldehydes.
作者:Juma'a R. Al Dulayymi、Mark S. Baird、Keith Jones
DOI:10.1016/j.tet.2003.11.006
日期:2004.1
3-(2S-Heptylcycloprop-1S-yl)propanoic acid 2-phenylethanamide was synthesised from cis-cyclopropan-1,2-dimethanol via enzymatic desymmetrisation of the dibutyrate; it gave identical NMR spectroscopic data to those reported for grenadamide but had an equal and opposite absolute rotation, indicating that the latter is the 2R,1R-enantiomer. (C) 2003 Elsevier Ltd. All rights reserved.
Carbohydrate-Derived Bis(oxazoline) Ligand in the Total Synthesis of Grenadamide
作者:Mike Boysen、Tobias Minuth
DOI:10.1055/s-0030-1258143
日期:2010.8
Using an optimised carbohydrate-based bis(oxazoline) ligand and copper(I) triflate, unactivated aliphatic alkenes were cyclopropanated with simple ethyl diazoacetate, giving the corresponding products in good yields and high stereoselectivities. The trans-disubstituted cyclopropyl carboxylic acid ester derived from 1-nonene was subsequently used as the key intermediate for the synthesis of the (+)-enantiomer