Synthesis of α-phenylthio enones and esters of α-phenylthio alkenoic acids

Abstract

The alkylation of anions from saturated and unsaturated ketones is described. a-Phenylthio enones (1) and the related esters (2) are in demand as Michael Diels-Alder dien~philes,~ and annelating agents.8 We report the synthesis of examples of these compounds which we have used to make extended enolate anions.9* O

Structural Modification of the Designer Stimulant α-Pyrrolidinovalerophenone (α-PVP) Influences Potency at Dopamine Transporters

“…α-PVP (7), as its hydrochloride salt, was prepared as previously reported 20 and was available from an earlier study. 13 Compounds 11 21,22 and 15 23 were prepared as hydrochloride salts according to literature procedures.…”

“…1 1-Phenyl-2-(piperidin-1-yl)pentan-1-one Hydrochloride (16). Piperidine (1.06 g, 12.45 mmol) was added to a stirred solution of 2bromo-1-phenylpentan-1-one ( 23) 20 (1.00 g, 4.15 mmol) in a mixture of anhydrous benzene (5 mL) and anhydrous Et 2 O (5 mL), and the reaction mixture was heated at 45 °C for 20 h under an N 2 atmosphere. The reaction mixture was diluted with Et 2 O (10 mL) and washed with H 2 O (2 × 10 mL).…”

Pummerer Cyclization Revisited: Unraveling of Acyl Oxonium Ion and Vinyl Sulfide Pathways

“…We were mindful of the previously reported challenges of cyclization on systems containing β-hydrogens. Not surprisingly, treatment of 7a with TFAA smoothly produced the corresponding vinyl sulfide 8a in excellent yield (92%) after 4 h. ,, Interestingly, use of other electrophiles (e.g., Tf 2 O or Ac 2 O) proved completely ineffective. This product is likely derived from slow ionization of the trifluoroacetoxy moiety followed by elimination of the β-hydrogen to produce the vinyl sulfide 8a .…”

A novel stereoselective synthesis of (Z)‐α‐arylsulfanyl‐α,β‐unsaturated ketones via Stille coupling of (E)‐α‐arylsulfanylvinylstannanes with acyl halides

“…For example, they have been used in preparation of 2,3-dihydrofurans [13], 1,4-and 1,5-dicarbonyl compounds [14], in the regioselective alkylation of cyclohexanones [11]. Some methods for the synthesis of α-arylthio-or alkylthio-α,β-unsaturated ketones have been developed including the Pummerer rearrangement of 2-arylsulfinyl ketones [15][16][17], the NaOH-catalyzed thiolysis of α,β-epoxyketones [18], and the Rh-catalyzed diazo decomposition of the β-thio group α-diazo ketones [19]. Despite considerable methodological differentiation, the reported procedures usually require starting materials which are not readily available, there still exists a need for new selective and convenient methods.…”