The dienolate aldol reaction of (E)-N-crotonoyl C(4)-isopropyl SuperQuat: asymmetric synthesis of α-vinyl-β-hydroxycarboxylic acid derivatives and conversion to α-ethylidene-β-hydroxyesters (β-substituted Baylis–Hillman products)

Di[(R)-2-ethylhexyl] Phthalate, a Bioactive Metabolite First Isolated from Three Different Bacillus Species, and its Synthesis

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Di(2-ethylhexyl) phthalate (DEHP) is the most common phthalate ester, which has been used as a plasticizer for the production of numerous polymers, particularly polyvinyl chloride (PVC). Many other groups have synthesized meso-DEHP indicating interest in this molecule, but we are the first to synthesize enantiomerically pure di[(R)-2-ethylhexyl] phthalate. We report herein, for the first time, the isolation - from the cultures of Bacillus thuringiensis, B. subtilis, and B. velezensis strains - of di[(R)-2-ethylhexyl] phthalate, enantiomerically pure and in good yields: its biological activity against bacteria and fungi was probed and for the first time its synthesis was done.

SuperQuat chiral auxiliaries: design, synthesis, and utility

The design, synthesis and outline of some of the most common synthetic applications of the SuperQuat (4-substituted 5,5-dimethyloxazolidine-2-one) family of chiral auxiliaries, developed to address the shortcomings of the Evans (4-substituted oxazolidin-2-one) family of chiral auxiliaries, are presented.

Organo-Catalyzed Regio- and Geometry-Specific Construction of β-Hydroxyl-α-vinyl Carboxylic Esters: Substrate Scope, Mechanistic Insights, and Applications

A green protocol has been developed for the synthesis of β-hydroxyl-α-vinyl carboxylic esters using aldehydes and α,β-unsaturated esters bearing an activated γ proton as starting materials under Morita-Baylis-Hillman (MBH) reaction conditions. Diverse β-hydroxyl-α-vinyl carboxylic esters have been synthesized regiospecifically in moderate to good yields with only E geometric selectivity. Other remarkable features include atom efficiency, environmental benignancy, and mild reaction conditions. Furthermore, the reaction products could be readily converted into tetrahydrofuran, dihydrofuran, and furan derivatives.

Synthesis of β- and β,β-substituted Morita–Baylis–Hillman adducts using a two-step protocol

The synthesis of a large number of β- and β,β-substituted keto esters was successful by the use of the Knoevenagel condensation reaction. The stereoselectivity of these reactions was improved by alteration of various substituent groups. Although there were few examples of complete Z selectivity, the use of tert-butyl acetoacetate with either aromatic or aliphatic aldehydes afforded Z selectivity. The selective reductions of these substituted keto esters was successfully achieved by using a combination of NaBH4 and CeCl3·7H2O or Yb(OTf)3, which allowed a facile synthesis of a large number of stereochemically pure substituted Morita–Baylis–Hillman adducts, including β,β-substituted adducts.