Limitations on the Persistence of Iminoxyls: Isolation of tert-Butyl 1,1-Diethylpropyl Ketiminoxyl and Related Radicals

Article abstract of DOI:10.1021/jo962136e

A series of iminoxyl radicals of the general formula R(C=NO^?)R¹, with R and R¹ usually tertiary, was synthesized in a search for radicals of increased persistence. Three new radicals were isolated as blue liquids: Et₃C(C=NO^?)Bu-t (1), t-C₅H₁₁(C=NO^?)Bu-t (2), and (t-C₅H₁₁)₂C=NO^? (3). Oxidation of oximes Et₃C(C=NOH)Ph (4H), PhCH₂CMe₂(C=NOH)Bu-t (5H), PhCMe₂(C=NOH)Bu-t (6H), and Me₂CH(C=NOH)C₅H₁₁-t (7H), among others, did not lead to isolable iminoxyls. A new, convenient synthesis of symmetrical tertiary imines from tert-RCl, tert-RCN, and Na is described. Radical t-Bu₂C=NO^? (8) and cyclohexene readily gave the allylic substitution product, 2,2,4,4-tetramethyl- 3-hexanone O-(2′-cyclohexen-1′-yl)oxime.

Full text of DOI:10.1021/jo962136e

2050
J . Org. Chem. 1997, 62, 2050-2053
Lim ita tion s on th e P er sisten ce of Im in oxyls: Isola tion of
ter t-Bu tyl 1,1-Dieth ylp r op yl Ketim in oxyl a n d Rela ted Ra d ica ls
Brian M. Eisenhauer, Minghui Wang,† Henryk Labaziewicz,‡ Maria Ngo,§ and
G. David Mendenhall*
Department of Chemistry, Michigan Technological University, Houghton, Michigan 49931-1295
Received November 15, 1996X
A series of iminoxyl radicals of the general formula R(CdNO•)R1, with R and R1 usually tertiary,
was synthesized in a search for radicals of increased persistence. Three new radicals were isolated
as blue liquids: Et3C(CdNO•)Bu-t (1), t-C5H11(CdNO•)Bu-t (2), and (t-C5H11)2CdNO• (3). Oxidation
of oximes Et3C(CdNOH)Ph (4H), PhCH2CMe2(CdNOH)Bu-t (5H), PhCMe2(CdNOH)Bu-t (6H), and
Me2CH(CdNOH)C5H11-t (7H), among others, did not lead to isolable iminoxyls. A new, convenient
synthesis of symmetrical tertiary imines from tert-RCl, tert-RCN, and Na is described. Radical
t-Bu2CdNO• (8) and cyclohexene readily gave the allylic substitution product, 2,2,4,4-tetramethyl-
3-hexanone O-(2′-cyclohexen-1′-yl)oxime.
Iminoxyl radicals, of the general formula R2CdNO•, are
of nitriles with alkyllithiums,7 or with Grignard reagents
in the presence of catalytic Cu(I).8 Hartzler showed that
di-tert-butyl ketimine could be prepared in good yield
from pivalonitrile and sodium.9 We have improved the
economy of this approach by the production of the
alkylation agent in situ from sodium and the correspond-
ing tertiary chloride:
intermediate in reactivity between carbon-centered radi-
cals and nitroxides. Di-tert-butyliminoxyl1 was the first
to be isolated in the pure state and has shown modest
synthetic utility.2 Since it decays slowly by irreversible
head-to-tail dimerization, we anticipated that replace-
ment of tert-butyl by sterically more demanding substit-
uents would strongly retard all of the known pathways
for decay. For instance, the (logarithmic) steric param-
eter ES declines from -1.54 for tert-butyl to -2.55 for
phenyl and -3.8 for Et3C.3 The preparation of a radical
of low molecular weight that could be stored indefinitely
at room temperature would greatly facilitate further
studies.
t-RCl + t-RCN + 2Na f t-R2CdNNa + NaCl
Syn th esis of Oxim es a n d Ra d ica ls. The synthesis
of ketimines from nitrile, chloride, and sodium conve-
niently avoids expensive, pyrophoric reagents. The
synthesis was accomplished inadvertently in one unsym-
metrical case as well. 2′,2′-Diethylpropiophenone oxime
(4H) was isolated from a reaction of sodium with tri-
ethylacetonitrile, followed by addition of hydroxylamine.
We inferred that the aromatic ring arose from contami-
nation of the starting nitrile with chlorobenzene appar-
ently added as a chaser solvent for distillation. Subse-
quent attempts to react pure triethylacetonitrile with
sodium followed by hydroxylamine did not give products
with sensible combustion analyses.
The unsymmetrical oximes other than 4H were syn-
thesized by the successive reaction of an alkyllithium and
hydroxylamine with the appropriate tertiary nitrile. The
unsymmetrical oximes displayed 1H-NMR spectra that
indicated a mixture of geometrical isomers, even though
the melting points were acceptably sharp. Since syn- and
anti-iminoxyl radicals equilibrate readily,10 the use of the
mixture of oximes in their synthesis was of no conse-
quence.
Bis(1-adamantyl) ketiminoxyl is the most persistent
iminoxyl isolated to date.4 We also sought in this study
to prepare polyradicals derived from 1,3-dibromoada-
mantane, with the eventual goal of synthesis of 3D
network polyradicals starting from known 1,3,5,7-tetra-
haloadamantanes.5
The precursors to isolable iminoxyls are sterically
hindered oximes. These are accessible from hindered
ketones and hydroxylamine under pressure,6 and more
conveniently by reaction of hydroxylamine with the
corresponding ketimine, available in turn by alkylation
† Present address: Department of Chemistry, State University of
New York at Stony Brook, Stony Brook, NY 11794.
‡ Present address: Department of Chemistry, University of Miami,
P.O. Box 249118, Coral Gables, FL 33124.
§ Present address: Environmental Analytical Research Laboratory,
Dow Chemical Co., Midland, MI 48641.
We encountered mixed success in the conventional
oxidation of the oximes to the corresponding radicals by
stirring with silver oxide in benzene. The wholly ali-
phatic, acyclic tertiary oximes gave isolable radicals. The
other iminoxyls were not isolable, but their ESR and
visible spectra could be measured easily. These details
will be reported elsewhere.
* Corresponding author. (906) 487-2359; FAX -2061; gdmenden@
mtu.edu.
X Abstract published in Advance ACS Abstracts, March 15, 1997.
(1) (a) Brokenshire, J . L.; Roberts, J . R.; Ingold, K. U. J . Am. Chem.
Soc. 1972, 94, 7040, and references therein. (b) Mendenhall, G. D.;
Ingold, K. U. J . Am. Chem. Soc. 1973, 95, 2963.
(2) (a) Mendenhall, G. D.; Cornejo, J . J .; Larson, K. D. J . Org. Chem.
1985, 50, 5382. (b) Mendenhall, G. D.; Ngo, M.; Larson, K. D. J . Org.
Chem. 1986, 51, 5390.
(3) Leffler, J . E.; Grunwald, E. Rates and Equilibria of Organic
Reactions; J ohn Wiley & Sons: New York, 1963; p 228.
(4) Lindsay, D.; Horswill, E. C.; Davidson, D. W.; Ingold, K. U. Can.
J . Chem. 1974, 52, 3554.
(5) (a) Khardin, A. P.; Novakov, I. A.; Radchenko, S. S. Zh. Org.
Khim. 1973, 9, 429. (b) Sollott, G. P.; Gilbert, E. E. J . Org. Chem. 1980,
45, 5405.
(7) Gregory, G. B.; J ohnson, A. L.; Ripka, W. C. J . Org. Chem. 1990,
55, 1479.
(8) Weiberth, F. J .; Hall, S. S. J . Org. Chem. 1987, 52, 3901.
(9) Hartzler, H. D. J . Am. Chem. Soc. 1971, 93, 4527.
(10) Gilbert, B. C.; Malatesta, V.; Norman, R. O. C. J . Am. Chem.
Soc. 1971, 93, 3290 and preceding papers in this series.
(11) Newman, M. S.; Fukunaga, T.; Miwa, T. J . Am. Chem. Soc.
1960, 82, 873.
(6) J ones, W. H.; Tristram, E. W.; Benning, W. F. J . Am. Chem. Soc.
1959, 81, 2151.
S0022-3263(96)02136-6 CCC: $14.00 © 1997 American Chemical Society

Limitations on the Persistence of Iminoxyls
J . Org. Chem., Vol. 62, No. 7, 1997 2051
The radical 6 derived from cumyl tert-butyl ketoxime
lacks easily abstractable H-atoms, and offered the pos-
sibility of facile synthesis of iminoxyls substituted on the
aromatic ring. However, we were disappointed to observe
that 6, obtained from oxidation of solutions of 6H,
decayed rapidly according to a second-order rate law.
Out of curiosity we also determined the effect of a
formal shift of a methylene unit from the (isolable) radical
8 as shown below:
For radical 1 this possibility is ruled out by the combus-
tion analysis, which does not agree with values calculated
for a radical with two fewer H-atoms. Second, if we
reduced samples of 3 with 1,3-cyclohexadiene immedi-
ately after preparation, or after standing 30 h at 0 °C,
the product after evaporation of volatiles displayed an
1H-NMR spectrum identical to that of the parent oxime,
with no significant resonances in the olefinic region.
Rea ction s of Di-ter t-bu tyl Ketim in oxyl (8) w ith
Cycloh exen e. The 1H-NMR spectrum of the adduct
between 8 and cyclohexene was virtually identical to that
of 2-cyclohexen-1-ol other than the presence of the two
tert-butyl resonances. We inferred that a 3-cyclohexenyl
radical was trapped by the oxygen atom of a second
iminoxyl radical. This reaction may be useful for allylic
functionalization of olefins under mild conditions.
8
7
One conformer of the isomer 7 has a “pocket” where
the oxygen might be expected to reside, which might
lower the tendency for it to abstract an H-atom from the
remote methylene group, while at the same time the
larger tert-pentyl might retard dimerization. However,
the stability of 7 was only comparable to that of the
related tert-butyl isopropyl ketiminoxyl,1b and it could not
be isolated.
Attempts to oxidize the difficultly-soluble adamantane
dioxime shown below under a variety of conditions always
gave colorless solutions that contained small amounts of
an unstable iminoxyl (ESR).
Exp er im en ta l Section
Reagent chemicals were purchased from commercial
sources. Olefins and oxidizable solvents were passed
through a short column of alumina before use.
Exact masses ((0.5 ppm) were measured by Mr. J ames
Windak, University of Michigan, with a VG Analytical
Model VG7250S. Conventional mass spectra were ob-
tained with an HP 5985B instrument. NMR spectra
(CDCl3 unless otherwise noted) were recorded on one of
several commercial instruments with g200 MHz field.
Combustion analyses were performed by Spang Labora-
tories, Eagle Harbor, MI.
The decompositions of the other, isolable iminoxyls
were not examined in detail. Radicals tert-butyl tert-
pentyl ketiminoxyl (2) and di-t-pentyl ketiminoxyl (3)
decayed slightly faster than the more heavily substituted
radical 1, but the stability of all three was increased by
dilution. The kinetics of decay, however, are not second
order and will be described elsewhere. Isolation of 9 from
1, and the virtual absence of nitriles or the parent ketone
Acyclic nitriles in this study were synthesized by
alkylation of phenylacetonitrile or the appropriate
butyronitrile (Aldrich) with sodamide and alkyl bromides
by the procedure of Newman.10 2,2-Dimethyl-3-phenyl-
propionitrile (HRMS m/ z calcd for C10H13N 159.1048,
found 159.1040) was reported by Moore12 but without
analytical details. 4,4-Diethyl-2,2-dimethyl-3-hexanone13
was prepared by refluxing the corresponding imine (0.60
g, 0.0030 mol, obtained as an intermediate as described
below) 4 h with 5 mL of 10% sulfuric acid followed by
extraction with hexanes (15 mL). The product was
isolated by bulb-to-bulb distillation below 1 torr: IR 2968,
2881, 1680, 1460, 1394, 1382, 1365, 1219, 1194, 1077,
1047, 1010, 992, 923, 856, 808 cm-1 1H-NMR δ 0.70(t,
.
9H, J ) 7.6 Hz), 1.212 (s, 9H), 1.67 (q, 6H, J ) 7.4 Hz).
Symmetrical tertiary imines were prepared by the
following representative procedure: Sodium (5.9 g, 0.26
g-atom) was dispersed in the usual way in boiling
xylenes, allowed to cool, washed with hexanes, and placed
in a 100 mL round-bottomed flask with 65 mL of hexanes
under argon. A mixture of pivalonitrile (8.3 g, 0.10 mol)
and tert-butyl chloride (9.3 g, 0.10 mol) was added
dropwise with magnetic stirring, and stirring was con-
tinued for a total of 1.5 h. The green mixture was then
hydrolyzed with water (20 mL) while maintaining its
temperature below 15 °C with an external ice bath. The
layers were separated, and the aqueous layer was washed
with 30 mL of hexanes. The combined, dried (Na2SO4)
among the decomposition products, are consistent with
an internal H-abstraction as the dominant mode of decay.
The HRMS (EI) of radical 2 showed a signal agreeing
with a value of M - 2H+ within 0.001 amu, while radical
3 showed mass values agreeing both with M - 2H+ and
M + 2H+, with the parent ions essentially absent from
both radicals. This outcome was consistent with a
disproportionation, e.g.
2 3 f 3H + CH2dCHCMe2C(dNOH)CMe2Et
Since the olefinic product of this reaction, like 3H itself,
should be oxidizable to the corresponding iminoxyl radi-
cal, and the normal syntheses of the radicals contained
silver oxide in excess, we became concerned that the
radicals sent for exact mass might actually have con-
tained the olefinic iminoxyls with two less mass units.
(12) Moore, J . S. Chiral Macromolecules Bearing Configurationally
Order Dipolar, Functional Groups: Molecular Design, Synthesis and
Phases. Ph.D. Thesis of University of Illinois at UrbanasChampaign,
1989, p 139.
(13) Bauer, P.; Dubois, J . E. J . Am. Chem. Soc. 1976, 98, 6999.

2052 J . Org. Chem., Vol. 62, No. 7, 1997
Eisenhauer et al.
organic layers were concentrated at aspirator pressure
the entire sample volume. A 2.03 g sample of 1 after 7
days was filtered from the solid portion (0.27 g), which
was crystallized successively from methanol and hexane
to give 0.20 g of a white solid, mp 101-103 °C, shown by
LCMS (HP 5988 equipped with thermospray interface,
90:10 MeCN:water, 45 °C, 1.0 mL/min, 2.1 × 200 mm
C-18) to contain 96% 1H. The presence of 1H in
decomposed 1 was also confirmed by HPLC (4.6 × 250
mm Rainin microsorb-MV C-18, 1 mL hexane/min, RI
detection), with one peak eluting at the same time (3.79
min) as authentic 1H.
1
to give di-tert-butyl ketimine (10.9 g, 77%), H-NMR δ
1.259 (lit.9 δ 1.24). Similarly, tert-amyl chloride and R,R-
dimethylbutyronitrile led to the corresponding imine
(59%) which was converted to 3H in 32% overall yield.
Unsymmetrical ketimines for this study were prepared
by reaction1b of a nitrile with tert-butyllithium (Aldrich)
or isopropyllithium (from the bromide and Li14). The
unpurified imines were converted to oximes by the
following representative procedure: Hydroxylamine hy-
drochloride (5.80 g, 83.5 mmol) and di-tert-butyl ketimine
(7.30 g, 51.6 mmol) were refluxed in methanol (30 mL)
for 3.5 h and then cooled to -40 °C for 15 min. The white
oxime 8H was filtered off and washed with cold water:
7.18 g after drying (88%), mp 156-7 °C (lit.6 mp 157.5-
8.5 °C). The oximes were purified by crystallization from
hexanes or methanol except for 4H, which was sublimed
several times <1 torr. (Additional data given as Sup-
porting Information.)
The first of about nine other peaks from the decom-
posed sample of 1 eluting from the column was collected
repeatedly. Concentration of the combined fractions gave
a few milligrams of colorless crystals, ascribed structure
9, mp 89-90 °C. HRMS (CI-CH4) m/ z calcd for C12H24
-
NO2 (M + H+) 214.1807, found 214.1801; other m/ z at
196 (M - OH)+, 140 (M - OH - C4H2)+, and 98 (Et2-
CCHMe+). 1H-NMR δ 0.74 (t, J ) 7.5 Hz, 3H), 0.94 (t, J
) 7.5 Hz, 3H), 1.21 (s, 9H), 1.49 (s, 3H), 1.52 (s, OH +
water impur), two diasteriotopic CH2 groups appeared
as a series of partially obscured multiplets (J ∼ 7.5 Hz)
centered approximately at 1.4, 1.7, 1.8, and 2.1. Decou-
pling experiments showed that the triplet at 0.74 was
coupled to the multiplets at 1.4 and 1.8, and the triplet
at 0.94 to those at 1.7 and 2.1. IR 3490 (s, br) 2995, 1590
(w), 1690, 1450, 1580, 1370, 1180, 1170, 1110, 900, 880,
+
1,3-Dipivaloyladamantane dioxime was synthesized
under N2 by introducing the corresponding dinitrile15
(1.01 g, 5.4 mmol) in toluene (8 mL) dropwise to vigor-
ously stirred tert-butyllithium (8.6 mL of 1.7 M in
pentane). The reaction flask was immersed in water at
room temperature. The mixture was stirred 24 h, and
the clear yellow solution was then hydrolyzed with
ethanol (5 mL) followed by water (5 mL). The organic
product was extracted with ether, dried (Na2SO4), and
concentrated to the pale green bis-imine (1.24 g, 76%,
IR 1594 cm-1). The crude bis-imine (1.2 g, 4.1 mmol),
methanol (35 mL), and hydroxylamine sulfate (1.16 g,
7.1 mmol) were refluxed 7 h and then allowed to stand
0.5 h at 0 °C: colorless crystals, 0.84 g (61%), after
recrystallization mp 237-9 °C (sealed tube). MS (CI,
830, 790 cm-1
.
The liquid portion of the decomposed radical in the
original experiment was analyzed by GC (1% in pentane,
HP 5985B GCMS, with a J W Scientific DB-5 capillary
column, 30 m × 0.32 mm × 0.25 µm film thickness, 170
°C; also for other analyses below). Comparison of peak
areas with standards revealed the presence of triethy-
lacetonitrile (2.1% based on original weight of radical)
and pivalonitrile (1%). (The presence of these nitriles
was confirmed by the presence of minor signals in both
13C- and 1H-NMR spectra of the decomposed radical
which increased after spiking with authentic samples.)
No 4,4-diethyl-2,2-dimethyl-3-hexanone (<0.4% present)
was detected upon injection of the pentane solution of
the liquid fraction of decomposed 1 on the same column
(5 min at 35 °C, followed by ramping to 245 °C at 10 °C/
min). The authentic ketone eluted after 14 min under
these conditions.
A sample of pure 1 that was allowed to decompose at
room temperature in a sealed tube subsequently dis-
played a 1H-NMR spectrum (CDCl3) from which, after
integration, we calculated maximum yields of 1H (34%)
and 9 (8%). The remaining material consists in part of
high molecular weight aggregates, since the LCMS of a
recrystallized fraction of the mixture displayed a peak
with m/ z 394 in addition to those of 9 and 1H.
Oxid a tion of Oth er Oxim es. A 0.1 M solution of 3
that had decomposed at 25 °C in benzene was concen-
trated to a white solid that was submitted for CI-MS
(probe). At the point of peak total ion current, masses
were observed corresponding to dimer m/ z 368 (2M -
1)+, 367, 200 (M + CH4+), 186 (M + H+), 98 (C5H11CHN+),
and 71 (C5H11+), among others.
A solution of R,R-diethylbutyrophenone oxime (4H, 66.2
mg, 0.269 mmol) in benzene (5 mL) was stirred 22 h with
silver oxide (318 mg, 1.37 mmol), filtered, and concen-
trated to 0.06 g of a red oil. A GCMS trace of the material
revealed eight peaks, with the largest eluted peak
ascribed to starting oxime (9.2 min). The next largest
(7.1 min) was ascribed to R,R-diethylbutyrophenone: m/ z
probe) m/ z 335 (M+ + 1), 261 (M+ - C4H9O), 234 (M+
-
C4H9CNOH), 160, 57, 41. (Additional characterization
in Supporting Information.)
ter t-Bu tyl 1,1-d ieth ylp r op yl k etim in oxyl (1). The
oxime 1H (1.8 g, 8.9 mmol) in benzene (50 mL) was
stirred vigorously with finely divided silver oxide (2.95
g, 12.7 mmol) for 5 h. The mixture was filtered and the
filtrate concentrated at 25 °C under reduced pressure to
give a blue liquid that was immediately purified by
elution through a short column of silica gel with 3-4 mL
of hexanes (alternatively basic alumina/pentanes). Con-
centration of the hexanes (vacuum line suitable, since
the radical has low volatility) gave pure 1, 1.7 g (96%), d
) 0.93 ( 0.03 g/cm3. IR 2980(vs), 2890(sh), 1610 (vs),
1470(vs), 1400, 1390, 1370, 1280, 1230, 1200, 1170, 1090,
1010, 960, 930, 860, 820, 680 cm-1
. Anal. Calcd for
C12H24NO: C, 72.67; H, 12.20; N, 7.06. Found: C, 72.43;
H, 12.06, N, 7.00.
The unstable radicals 2 and 3 were synthesized from
their parent oximes in exactly the same way. Since
combustion analysis was no longer available locally, their
identity was assumed to follow from their mode of
formation, characteristic ESR spectra, blue color, and
intense IR absorption at 1607 cm-1 and the absence of
OH and CdO absorptions.
An a lysis of Ra d ica l Decom p osition P r od u cts.
Samples of 1 on standing lost their blue color within a
few days and deposited colorless crystals that slowly filled
(14) Gilman, H.; Langham, W.; Moore, F. W. J . Am. Chem. Soc.
1940, 62B, 2327-35.
(15) Shvekhgeimer, G. A.; Kuz’micheva, L. K. Khim. Geterotsikl.
Soedin. 1976, 12, 1654.

Limitations on the Persistence of Iminoxyls
J . Org. Chem., Vol. 62, No. 7, 1997 2053
204 (M+), 189 (M+ - CH3), 175 (M+ - Et), 105 (PhCO+),
99 (Et3C+), 98 (Et3C+ - H), 77 (Ph+), 57 (C4H9+).
The crude oxidation product from cumyl tert-butyl
ketoxime (6H) and silver oxide, obtained similarly,
displayed m/ z (CIMS probe) 220 (oxime + H+), 437
(dimer + H+), and 119 (cumyl+), among other minor
signals.
2. Di-tert-butyl ketiminoxyl effects facile allylic sub-
stitution on cyclohexene to give the corresponding O-
substituted allylic oxime ether.
3. Although groups larger than tert-butyl can prevent
head-to-tail dimerization of iminoxyls, internal H-ab-
straction can limit their kinetic stability, even when an
R-CH is lacking.
Rea ction of 8 w ith Cycloh exen e. A stock solution
of the radical (0.13 M) in pentane was concentrated at
aspirator pressure to a blue liquid. The neat radical (222
µL, 1.17 mmol) was mixed with redistilled cyclohexene
(277 µL, 2.73 mmol) and allowed to react for 1 h at 25 °C
during which a portion of 8H crystallized. The mixture
was diluted with 0.5 mL pentane and allowed to stand
at -60 °C for 1 h. The supernatant was pipetted off and
passed through a short column of basic alumina con-
tained in a disposable pipette to remove any remaining
8H, and the column was washed with pentane. The
eluate and washings were concentrated to give 78.9 mg
(60%; upon repetition, 83%) of 2,2,4,4-tetramethyl-3-
hexanone O-(2′-cyclohexen-1′-yl)oxime as a colorless,
fragrant liquid (97% pure by GC/column 160 °C). 1H-
NMR: δ5.85 (m, 2H), 4.46 (m, 1H), 1.59-1.93 (m, 6H),
1.34 (s, 9H), 1.21 (s, 9H). IR (neat): 2950, 1490, 1450,
1400, 1370, 1320, 1250, 1200, 1180, 1040, 970, 920, 750
cm-1. MS (EI): m/ z 236, 158, 140, 97, 84, 57, 41; HRMS
(CI/NH3) m/ z calcd for C15H28NO (M + H+ ) 238.2171,
found 238.2164.
Ack n ow led gm en t. This work was carried out with
support from the U. S. Army Research Office (grant
DAAG 29-78-C-001), the donors of the Petroleum Re-
search Fund, administered by the American Chemical
Society, an undergraduate fellowship to M.N. from the
Dean’s office of MTU, and a Dow Undergraduate Sum-
mer Fellowship to B.E. We also thank Mr. Thomas
Neils, Mr. Brent Walchuk, and Mr. Kent R. Larson for
experimental assistance, Mr. David Lindsay at the
National Research Council of Canada, Ottawa, for the
LCMS analyses, and Mr. J erry Lutz for conventional
mass spectra.
Su p p or tin g In for m a tion Ava ila ble: A table of melting
points, combustion analyses or exact mass values, and 1H-
NMR data for new oximes described herein (1 page). This
material is contained in libraries on microfiche, immediately
follows this article in the microfilm version of the journal, and
can be ordered from the ACS; see any current masthead page
for ordering information.
Su m m a r y
1. The seven new monooximes of this study gave
isolable radicals when both alkyl groups were tertiary
and not aromatic.
J O962136E