Nucleophilic opening of the oxirane ring of 1-methyl-4-phenyl-3,4-epoxypiperidine

Abstract

The opening of the oxirane ring of l-methyl-4-phenyl-3,4-epoxypiperidine (1) by reduction with lithium aluminum hydride 'or diborane occurs by a displacement at the 4 position to give cis-l-methyl-4-phenyl-3-piperidinol. The reaction of 1 with Grignard or lithium reagents gives an elimination reaction a t room temperature to form l-methyl-4-phenyl-l,2,3,6-tetrahydro-3-pyridinol, although a t higher temperatures addition does occur. The reaction pathways are considered.

Theoretical study of catalytic hydrogenation of oxirane and its methyl derivative

“…The transition state is characterised by a vibration with a negative frequency (-381.55 cm On the basis of these results, a probable mechanism of the oxirane hydrogenation in the presence of the aluminium chloride was proposed (Figure 7). The opening of oxirane ring is occurred in accordance with the literature data [17][18][19][20] Figure 7. Reaction scheme (a) and probable mechanism of oxirane hydrogenation in the presence of AlCl 3 (b).…”

“…The opening of methyloxirane ring is occurred in accordance with the literature data [17][18][19][20]22 Figure 13. Reaction scheme (a) and probable mechanism of methyloxirane hydrogenation in the presence of AlCl 3 (b).…”

Small charged rings. X. Expansion of the aziridinium ring by reaction with nitrones

“…(complex multiplet, CH2-CH2), 8.52 and 8.81 (s,s, (CH3)2CO), From 4.95 g (15 mmoles) of 1-benzyl-l-ethyl-l-azoniaspiro-[2.5]octane perchlorate (14) and 4.45 g (35 mmoles) of nitrone 2a there was obtained 6.11 g (89%) of 5-benzyl-5-ethyl-8,9,9-trimethyl-2-oxa-l-aza-5-azoniabicyclo[4.3.0]nonane-3-spiro-l'-cyclohexane perchlorate (15a). An analytical sample, colorless prisms from acetonitrile-ether, had mp 149-150°; no infrared maxima corresponding to O-H or N+-H: nmr (in CDC13) at r 2.50 (s, C6H5), 5.52 (s, ArCH2N~), 5.6-.0 (m, NCHN+), 6.0-6.6 (unresolved multiplet, CH3CH2N+), 6.27 and 6.97 (AB system, J = 14.0 cps, OCH2N+), 7.5-8.2 (m,m, CH3CH and CCH2C), 8.2-8.7 (unresolved multiplet, (CH.…”

“…Distillation of the residual liquid through a 12-in. spinning-band column yielded N-[2-methyl-2-(2',2',3'trimethylpyrrolidin-l'-oxy)propyl]dimethylamine (11a) as a clear colorless liquid: bp 61.0-62.5°( 1.0 mm); pKa 8.6 (in 66% dimethylformamide) ;24 no O-H or N-H bands in the infrared spectrum; nmr (in CDCla) at 6.8-7.3 (unresolved multiplet, CH2NO), 7.72 s, (CH3)2N), 7.75 (s, (CH3)2NCtf2), 8.1-8.6 (m, CH3CH and CCH2C), 8.82 (s, (CH3)2CO), 8.97 and 9.20 (s,s, (CH3)2CN), 9.14 (d, CEfsCH); nmr (in CF3COOH) at 6.80 (d, J = 4.5 cps, (Ctf3)2N+H).…”

“…a charged, five-membered cycle. [6][7][8] They appear to proceed by opening of the aziridinium ring to the more stable of two possible tertiary /3-aminocarbonium ions, which combines with the polarized carbonyl or nitrile group to form the appropriate five-membered heterocycle. We now report an extension of the scope of such ring enlargements to include a new type, ©+ + 3 -> ®+, where the adding group is a 1,3-dipole in general, a nitrone (azomethine N-oxide) in this particular case (eq 3).…”