A Convenient Synthesis and Chemical Properties of 3-Acylamino-6-poly­fluoroalkyl-2H-pyran-2-ones

Abstract

A number of 3-acylamino-6-polyfluoroalkyl-2H-pyran-2-ones 3 were synthesized from b-alkoxyvinyl polyfluoroalkyl ketones 1 and N-acylglycines 2 in acetic anhydride in high yield. The reactions of trifluoromethyl-containing 2H-pyran-2-one 3b with Oand N-nucleophiles were studied and 3-N-benzoylamino-6-hydroxy-6-trifluoromethyl-5,6-dihydro-2H-pyran-2-one (13), 3-Nbenzoylamino-6-hydroxy-6-trifluoromethyl-5,6-dihydro-2H-pyridin-2-one (14a), and N-and O-substituted 3-(N-benzoylamino)-6-trifluoromethyl-2H-pyridin-2-ones (15c,e, and 16) were synthesized.

Synthesis of New δ‐(Polyfluoroalkyl)‐δ‐hydroxy‐α‐amino Acids

“…Consequently, the major products were compounds 6c and 7c, identical to the products obtained from pyrone 3c. Compounds 2c and 10 [9] ( Figure 2) were also isolated from the reaction mixture as by-products in 20 % and 6 % yields, respectively.…”

“…We have previously reported the synthesis [9] and reactivities [9,10] of pyrones 3, which in this paper have served as convenient precursors of the target amino acids 1 and 2. The pyrones 3 have the same carbon skeletons and necessary functional groups.…”

Thermal Diels–Alder Reactions of 3‐(Benzoylamino)‐6‐(polyfluoroalkyl)pyran‐2‐ones – New Synthesis of p‐(Polyfluoroalkyl)anilines

“…The X- ray analysis proved that the benzamido group and the oxygen atom were attached in an ortho relationship, and that the H 15 and H 16 protons have a cis configuration (Figure 3). Some chemical transformations with p-(trifluoromethyl) anilides 5a, 5f and 5g have also been investigated.…”

“…We found that the heating of pyrone 1a [16] with α-fluorostyrene (2) [9] in toluene gave only one of the possible regioisomeric products, the phenyl-substituted N-benzoyl-4-(trifluoromethyl)aniline 5a in a very slow reaction (toluene, sealed tube, 120°C, 34 d, 43 % yield, 32 % of pyrone 1a was recovered) (Scheme 1). Interestingly, the reaction of β-fluorostyrenes 7 [17] with pyrone 1a gave the same product in Scheme 1. 54 % yield after 40 d at 120°C (34 % of pyrone 1a was recovered).…”

“…The N-[2-oxo-6-(polyfluoroalkyl)-2H-pyran-3-yl]benzamides [16] and fluorostyrenes [9,17] were prepared according to literature procedures. …”