Wittig Reactions in Water Media Employing Stabilized Ylides with Aldehydes. Synthesis of α,β‐Unsaturated Esters from Mixing Aldehydes, α‐Bromoesters, and Ph₃P in Aqueous NaHCO₃.

Abstract

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Syntheses and evaluation of the antioxidant activity of acitretin analogs with amide bond(s) in the polyene spacer

“…This ester was easily isolated through routine flash column chromatography (FCC) in 34% yield. On the other hand, O-tert-butyl fumarate (22) was synthesized through a Wittig reaction of the commercially available glyoxylic acid monohydrate with the stabilized phosphorane Ph 3 P]CHCO 2 tBu in DMF at RT [7], followed by aqueous work-up. The thus obtained ester 22 had the E configuration, as shown by 1 H NMR.…”

Tandem-, Domino- and One-Pot Reactions Involving Wittig- and Horner-Wadsworth-Emmons Olefination

“…Frequently, Wittig olefination reactions are carried out with in situ prepared phosphonium salts and phosphoranes [17,[22][23][24][25][26][27]. One-pot oxidation-Wittig olefination reactions are also quite common [40,, especially when the carbonyl component is labile [89,97].…”

“…This reaction procedure has been diversified further by a one-pot preparation of benzyltriethylphosphonium bromides from the air-stable triethylphosphine hydrobromide and benzyl alcohols and subsequent Wittig olefination with aromatic aldehydes in aqueous medium [21]. Simultaneous mixing of alkyl halide such as α-haloesters (e.g., 13), α-halonitriles, α-halocarbonyl compounds and α-alkyl-α-halocarbonyl compounds, triphenylphosphine (12), and carbonyl compound (e.g., 11, 15, 18) in the presence either of a base [17,[22][23][24][25][26] or an alkene [27] was shown to give α,β-unsaturated esters [17,[22][23][24][25][26][27] (e.g., 14, 17, 19), α,β-unsaturated nitriles [23,26] and enones [27], respectively (Scheme 3). Epoxides are stable under these reaction conditions as can be seen in the transformation of 18 to 19 (Scheme 1).…”

Fluorinated Beta-diketo Phosphorus Ylides Are Novel Efflux Pump Inhibitors in Bacteria

“…Organic compounds of phosphorus ylides (P-ylides) are a fascinating class of compounds (7). The biological activity of P-ylides related to their ATP-binding cassette subfamily B member 1 (ABCB1)-modulating activity in mouse lymphoma cells has already been described (8), however, additional information is needed to describe their valuable biological activities in other aspects.…”