81818-92-0Relevant academic research and scientific papers
Crossed aldol reaction using cross-linked polymer-bound lithium dialkylamide
Seki, Atsushi,Ishiwata, Fusae,Takizawa, Youichi,Asami, Masatoshi
, p. 5001 - 5011 (2007/10/03)
Cross-linked polymer-bound lithium dialkylamides were employed in crossed aldol reaction of various carbonyl compounds with aldehydes to afford the corresponding β-hydroxycarbonyl compounds. The introduction of spacer chains to the polymer-bound lithium d
HIGHLY ANTI DIASTEREOSELECTIVE REDUCTION OF 2-ALKYL-3-OXO AMIDES BY POTASSIUM TRIETHYLBOROHYDRIDE
Ito, Yoshio,Katsuki, Tsutomu,Yamaguchi, Masaru
, p. 4643 - 4646 (2007/10/02)
Potassium triethylborohydride was found to reduce 2-alkyl-3-oxo amides to the corresponding 3-hydroxy amides with excellent anti-diastereoselectivity (>99:1), and in combination with asymmetric acylation, a useful route to optically active anti-2-alkyl-3-
ACYCLIC STEREOSELECTION-13; ARYL ESTERS: REAGENTS FOR THREO-ALDOLIZATION
Heathcock, Clayton H.,Pirrung, Michael C.,Montgomery, Stephen H.,Lampe, John
, p. 4087 - 4095 (2007/10/02)
Preformed Li enolates of hindered aryl esters condense with aldehydes to give predominantly threo aldols.The method has been explored with esters 3 (DMP propionate), 4 (BHT propionate), 5 (DBHA propionate).DMP propionate reacts with benzaldehyde and α-unbranched aliphatic aldehydes to give threo:erythro ratios of about 6.5:1.However, with α-branched aliphatic aldehydes, ester 3 gives only threo-aldols.BHT propionate and DBHA propionate give only threo-aldols with all aldehydes studied.The DMP aldols may be converted into β-hydroxy acids by simple hydrolysis with KOH in aqueous methanol.BHT aldols cannot be hydrolyzed without retroaldolization.However, these aldols can be reduced to diastereomerically pure 1,3-diols.The DBHA aldols can converted into β-hydroxy acids by a method involving oxidation with ceric ammonium nitrate (CAN) in aqueous acetonitrile.Threo-selectivity is also seen in the condensations of DMP butyrate (15), DBHA butyrate (16), DMP pentenoate (17), and BHT pentenoate (18).The approach has been utilized in a stereoselective synthesis of racemic methyl corynomycolate.
