Herstellung und Umsetzungen von (R,R)‐ und (S,S)‐3‐Trifluormethyloxiran‐2‐carbonsäure‐ethylester, einem vielseitigen, leicht zugänglichen CF₃‐haltigen Synthesebaustein

Abstract

A facile three-step route has been elaborated leading from furnish novel enantiomerically pure trifluoromethyl-substi-4,4,4-trifluoro-3-oxobutanoate to the trifluoro glycidic ester 1 tuted carboxylic esters, ketones, diols, and epoxy alcohols. The mentioned in the title (0.1-mole scale). Reactions with azide latter ones undergo selective isomerizations by Payne rear-(+ 4,5) and with organometallic compounds such as cuprates rangement (11 -+ 12) in aqueous NaOH/acetone or tert-butyl (+ 3,6), lithium (-+ 7,8), and magnesium derivatives (+ 9 -11) alcohol.

Joy and Flustration with Organofluorine Compounds – A Fluorous Autobiography

“…Dramatic differences of reactivities and properties, as compared to non-fluorinated analogs, have been reported in these investigations. [17] c) A chiral dendrimer consisting of triol ether moieties prepared by addition of the trifluoromethyl-substituted dioxanone Li-enolate to pivalaldehyde (center part) and to 4-TBDPS-O-CH 2 -benzaldehyde (branching points). The inner three and the outer nine F 3 C-groups are all constitutionally heterotopic, and their 19 F-NMR signals are, at least partially, resolved (four of the expected six signals are seen for the inner and eight of the maximum 18 for the outer F 3 C groups).…”

Practical asymmetric synthetic route to 4,4,4‐trifluoro‐3‐hydroxybutyrate: Head‐to‐tail and head‐to‐head crystallizations through double and single hydrogen bonds of hetero‐ and homochiral 4,4,4‐trifluoro‐3‐hydroxybutyrophenones

“…2,3 Chiral organofluorine compounds have played an important role in pharmaceutical chemistry and opto-electronic material science. 4 Despite the synthetic importance of 4,4,4-trifluoro-3-hydroxybutyric acid derivatives, 5 the asymmetric syntheses of these compounds have been quite limited. 6 Herein, we report the practical asymmetric synthesis of 4,4,4-trifluoro-3-hydroxybutyric acid derivatives via (1) head-to-tail, and (2) head-to-head assembly of hetero-and homochiral crystals of 4,4,4-trifluoro-3-hydroxybutyrophenone followed by the Baeyer-Villiger oxidation reaction 7 by trifluoroperacetic acid (Scheme 1).…”

Electronically Promoted Payne Rearrangement of 3-CF3-2,3-Epoxyalcohols

“…This basic information in hand, we have devised a utilization of this anion-stabilizing ability to the Payne rearrangement of 3-CF 3 -2,3-epoxyalcohols which led to the anticipation of a single product due to the expected strong equilibrium preference between two isomeric materials. In this communication we describe our preliminary results on this topic, realizing the efficient stereodivergent construction of regioisomeric target epoxyalcohols from a single α,β-unsaturated ketone by way of this unique pathway as the key step.…”