73198-88-6Relevant articles and documents
Synthesis of Ynolates via Double Deprotonation of Nonbrominated Esters
Sun, Jun,Yoshiiwa, Toshiya,Iwata, Takayuki,Shindo, Mitsuru
supporting information, p. 6585 - 6588 (2019/09/30)
Herein, we report a double deprotonation method used for the preparation of ynolates starting from nonbrominated 2,6-di-tert-butylphenyl esters. The current method is superior to the previously described double lithium/halogen exchange approach because easily accessible starting materials are used. This method will be especially useful for preparation of ynolates bearing functional groups in organic synthesis.
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.