An efficient procedure for the synthesis of 2-N-Boc-amino-3,5-diols
摘要:
AWe wish to describe here the diastereoselective reaction between chiral N-Boc-alpha-amino aldehydes with both achiral allyltrichlorostannanes leading to 1,2-syn-N-Boc-alpha-amino alcohols, which are easily converted to the corresponding 4-N-Boc-amino-3-hydroxy ketones after treatment with catalytic amounts of OsO4 in the presence of NaIO4. After reduction of the carbonyl function, these 4-N-Boc-amino-3-hydroxy ketones were converted to 1-deoxy-5-hydroxy sphingosine analogues. (C) 2008 Elsevier Ltd. All rights reserved.
Controlling stereochemistry in polyketide synthesis: 1,3- vs. 1,2-asymmetric induction in methyl ketone aldol additions to β-super siloxy aldehydes
作者:Patrick B. Brady、Brian J. Albert、Matsujiro Akakura、Hisashi Yamamoto
DOI:10.1039/c3sc51183a
日期:——
The aldol addition of methyl ketones to β-siloxy and α-methyl β-siloxy aldehydes is described. Careful control of mechanistically distinct aldol reactions leverages 1,2- and 1,3-asymmetric induction, selectively forming syn and anti aldol adducts with excellent diastereocontrol. Experimental and theoretical investigations have provided insight to the factors governing diastereoselectivity.