DIBAL-Mediated Reductive Transformation of trans-Dimethyl Tartrate Acetonide into ε-Hydroxy α,β-Unsaturated Ester and Its Derivatives

Abstract

Step-wise, selective DIBAL reduction of the acetonide diester derived from tartaric acid, followed by the Horner-Emmons reaction effectively provided desymmetrized hydroxy mono-olefination products in one-pot operation.

One-pot synthesis of enantiomerically pure N-protected allylic amines from N-protected α-amino esters

“…Likewise, the results obtained for ( E )- 2a , the use of stabilized ylides ( Table 2 , entries 3 and 4) provided the expected E alkenes. In the particular case of the α-cyano phosphorane reagent, complete stereoselectivity was not achieved ( E : Z ratio of 5:1) as it has been previously observed in similar reactions [ 26 ]. Fortunately, both products were easily separated by column chromatography.…”

Stereoselective synthesis of backbone extended π-conjugated amino esters

“…To introduce another double bond on these (E)-α,β-unsaturated γ-amino acids, it is essential to convert the ethyl esters of (E)α,β-unsaturated γ-amino acids into corresponding allylic alcohols and subsequently aldehydes. As DIBAL-H is known for the selective reduction of ethyl esters into corresponding alcohols in the presence of conjugated double bonds, 21,22 we anticipated that it can selectively reduce ethyl esters of 1a-1g to corresponding allylic alcohols 2a-2g. We subjected amino esters 1a-1g, for the DIBAL-H reduction.…”

Aluminum Acetals in Organic Synthesis

“…Tomioka et al recently reported a stepwise one‐pot procedure for the desymmetrization of trans ‐dimethyl tartrate acetonide 45a. The diester was treated first with two equivalents of DIBAL‐H at 0 °C, then with one equivalent at –78 °C, and eventually with the anion of a phosphonate derivative (Scheme ).…”