Stereoselective divergent synthesis of 1,2-aminoalcohol-containing heterocycles from a common chiral nonracemic building block
摘要:
gamma-N,N-Dibenzylamino-beta-hydroxysulfoxide 1 proved to be an excellent chiral building block for the synthesis of a range of 1,2-amino alcohol-containing heterocycles. Thus, I was converted into 4,5-disubstuted oxazolidin-2-one 4 and aminoepoxides 2 and 3. Aminoepoxide 2 proved to be an excellent precursor to access oxazolidin-2-one 5 and azetidin-3-ol 6. Finally, 2 was used as a key intermediate that allowed the development of a divergent strategy to access cis-2-methyl-6-substituted piperidin-3-ol alkaloids. (+)-Deoxocassine 7 and a C-6 ethyl analogue 8 were prepared to illustrate this approach and to demonstrate that this strategy should be adaptable to the production of other members of this alkaloid family. (C) 2015 Elsevier Ltd. All rights reserved.
A Route to “all-cis” 2-Methyl-6-Substituted Piperidin-3-ol Alkaloids from syn-(2R,1′S)-2-(1-Dibenzylaminomethyl)epoxide: Rapid Total Synthesis of (+)-Deoxocassine
作者:Pierre-Yves Géant、Jean Martínez、Xavier J. Salom-Roig
DOI:10.1002/ejoc.201101333
日期:2012.1
to the synthesis of two cis-2-methyl-6-substituted piperidin-3-ols is described. syn-(2R,1′S)-2-(1-Dibenzylaminomethyl) epoxide (13) was used as common building block. The key step involved oxirane ring opening of 13 by the nucleophilic lithium aza-enolate of hydrazones 12a and 12b. Subsequent hydrazone hydrolysis and intramolecular reductive amination afforded the alkaloid (+)-deoxocassine and a new
Highly Enantioselective Access to α-Dibenzylamino Ketones from Chiral Nonracemic α-Bromo α′-Sulfinyl Ketones by Dynamic Kinetic Resolution: Synthesis of (2R,1′S)-2-[1-(Dibenzylamino)alkyl]oxiranes
作者:Pierre-Yves Géant、Jean Martínez、Xavier J. Salom-Roig
DOI:10.1002/ejoc.201001403
日期:2011.3
A novel and efficient synthesis of enantiomerically pure alpha-dibenzylamino alpha'-sulfinyl ketones starting from a mixture of both epimers of alpha-bromo alpha'-(R)-sulfinyl Ketone has been realized through combined in situ substitution-epimerization in so-called Dynamic Kinetic Resolution (DKR). The scope of the reaction has been examined, and four differently substituted alpha-(S)-dibenzylamino