New Method for Synthesis of Various Types of Substituted 2(5H)-Furanones

Abstract

A combination of the reaction of dianions of (phenylthio) acetic acid and its homologs with epoxides, the conjugate addition reaction of 3-phenylthio-2-(5H)-furanones with carbanion species, and the α-alkylation reaction of α-phenylthio-γ-butyrolactones is shown to provide a general method for the synthesis of a variety of substituted α-phenylthio-γ-butyrolactones. Oxidation of these α-phenylthiolactones to the corresponding sulfoxides, followed by pyrolysis furnishes all the types of substituted (3-, 4-, and 5-mono-; 3,4-, 3,5- 4,5-, and 5,5-di-; 3,4,5-tri-) 2(5H)-furanones in good overall yields.

Structure–activity relationships of analogs of 3,4,5-trimethylfuran-2(5H)-one with germination inhibitory activities

“…They are, however, either multistep reactions, or provide 2 in low yield (Iwai et al, 1977;Sato et al, 1977;Shindo et al, 2006). Our syntheses of the presented analogs of the germination inhibitor 3,4,5-trimethyl-2(5H)-furanone (2) that possesses germination inhibitory activity as described by Light et al (2010), is based on the procedure recently published by Surmont et al (2010).…”

New rearrangement reactions of α-phenylsulphinylacrylate derivatives

“…Oxidation of the phenylthio-derivative (29) lo with m-chloroperbenzoic acid afforded a mixture of products, which, without separation, was treated with pyridine-water to yield the hydroxy-ester (25) (23%) and a 1 : 1 mixture of two stereoisomers of the sulphinate derivative (30) (28yO).l3 Compound (30) was identified by its n.m.r. 0-SPh B J 67 CO, Me 573 spectrum, its stability to pyridine-water, and its smooth conversion to the hydroxy-ester (25) on treating with sodium methoxide in methanol ; its formation provides additional evidence for the reaction sequence (26)+(27)+ Other a-phenylsulphinylacrylates (13) , ( 16) , (17), ( 18), and (19) also underwent the rearrangement induced by pyridine-water under refluxing condition to give the corresponding hydroxy-esters : a mixture of (31) and (32) [inseparable; total 52% (ca. 5 : 1) from (E)-(13); total 51% (ca.…”

“…Compound (67) was prepared by oxidation of the phenylthiobenzofuranone (22), which was synthesised from the known saturated derivative (66) l9 by treatment with trifluoroacetic anhydride. 16 The results of the reactions of (67) are summarised in Scheme 13, from which it is clear that in both the vinylogous Pummerer and sequential prototropic shift and allylic sulphoxide-sulphenate rearrangement reactions a hydroxy or acetoxy group was exclusively introduced at the carbon atom attached to the lactonic ethereal oxygen atom, giving rise to com- …”

“…Methyl (E)-and (Z)-2-(phenylsulphinyl)pent-2-enoate (16). Compound (16) (0.47 g, 83%; the analytical sample was purified by preparative t.1.c.)…”

“…C1,Hl2O2S requires C, 65.4; H , 5.5%).5-Methyl-3-(phenylthio) furan-2(5H)-one (20) .-The 3-(phenylthio)furan-2(5H)-one (20) (0.024 g,10%) was obtained from the a-phenylsulphinylacrylate(16) (0.27 g) and identified by comparison with an authentic sample.ls 4-Methyl-3-(phenylthio) furan-2(5H)-one (21) .-The 3-(phenylthio)furan-2(5H)-one (21) (0.08 g, 24%) was obtained from the a-phenylsulphinylacrylate (17) (0.4 g) ; m.p. 5 0 -5 1 "C (crystallised on standing, washed with carbon tetrachloride); vmX.…”