2218 J . Org. Chem., Vol. 61, No. 6, 1996
Notes
123.87, 124.27 (CH), 131.20, 135.11, 138.07, 172.05 (C); MS m/ z
(rel int) 277 (M+, 1), 208 (M+ - C5H9, 8), 194 (M+ - C6H11, 1),
154 (M+ - C9H15, 2), 141 (5), 140 (C8H14NO+, 7), 121 (12), 87
(21), 72 (CONMe2+, 100), 69 (26), 41 (36).
(CONMe2) cm-1; 1H NMR (400 MHz) δ 0.95 (s, 6H), 1.56 (s, 3H),
1.67 (s, 3H), 1.87 (t, 6.3, 2H), 2.04 (s, 4H), 2.92, 2.99 (2 s, 6H),
3.06 (d, 6.7, 2H), 5.33 (t, 6.7, 1H); 13C NMR (100 MHz) δ 16.47,
19.76, 28.54, 35.46, 37.33 (CH3), 19.46, 27.63, 32.68, 33.60, 39.75,
40.07 (CH2), 116.26 (CH), 34.90, 127.04, 136.83, 138.91, 172.06
(E,Z)-4,8,12-Tr im eth yl-3,7,11-tr id eca tr ien oic a cid N,N-
d im eth yla m id e (4b): tR 38.95; IR 1648 (CONMe2) cm-1
;
1H
(C); MS m/ z (rel int) 277 (M+, 2), 142 (26), 141 (19), 140 (C8H14
-
NMR (400 MHz) δ 1.55 (br s, 6H), 1.63 (s, 3H), 1.70 (s, 3H), 2.88,
2.95 (2 s, 6H), 3.03 (d, 6.7, 2H), 5.01-5.10 (m, 2H), 5.29 (td, 6.7,
1.3, 1H); 13C NMR (100 MHz) δ 15.85, 17.56, 23.30, 25.56, 35.36,
37.23 (CH3), 26.06, 26.56, 32.13, 33.14, 39.60 (CH2), 117.51,
123.68, 124.16 (CH), 131.20, 135.34, 138.03, 171.87 (C); MS m/ z
(rel int) 277 (M+, 1), 208 (12), 195 (1), 154 (2), 141 (5), 140 (35),
121 (15), 87 (19), 72 (CONMe2+, 100), 69 (29), 41 (47).
NO+, 7), 126 (C7H12NO+, 5), 95 (17), 87 (7), 72 (CONMe2+, 100),
41 (20).
(Z)-4-Meth yl-6-(2′,6′,6′-tr im eth ylcycloh ex-1′-en yl)-3-h ex-
en oic a cid N,N-d im eth yla m id e (14b): tR 39.86; IR 1649
(CONMe2) cm-1; 1H NMR (400 MHz) δ 0.98 (s, 6H), 1.61 (s, 3H),
1.76 (d, 1.2, 3H), 1.88 (t, 6.3, 2H), 1.97-2.07 (m, 4H), 2.91, 2.97
(2 s, 6H), 3.07 (d, 6.8, 2H), 5.28 (td, 6.8, 1.2, 1H); 13C NMR (100
MHz) δ 19.77, 23.28, 28.54, 35.46, 37.26 (CH3), 19.43, 26.85,
32.69, 32.87, 33.22, 39.71 (CH2), 116.96 (CH), 34.90, 127.20,
136.80, 138.87, 171.93 (C); MS m/ z (rel int) 277 (M+, 2), 142
(16), 141 (18), 140 (29), 126 (5), 95 (16), 87 (16), 72 (100), 41
(22).
(E)-4-Meth yl-6-(2′,6′,6′-tr im eth ylcycloh ex-1′-en yl)-3-h exen -
1-ol (15a ). (E)-Amide 14a (476 mg, 1.72 mmol) was treated with
superhydride (3.5 mL) for 4.5 h under the same conditions
described for 4a , to yield a residue (398 mg) which, after silica
gel purification, afforded 15a (348 mg, 85.7%, hexane:t-BuOMe
75:25) (lit.12c): tR 31.21; IR 3337, 1047 (OH) cm-1; 1H NMR (400
MHz) δ 0.98 (s, 6H), 1.59 (s, 3H), 1.68 (s, 3H), 1.89 (t, 6.3, 2H),
2.05 (s, 4H), 2.29 (br q, 7.3, 6.6, 2H), 3.63 (q, 6.2, 2H), 5.15 (br
t, 7.3, 1H); 13C NMR (100 MHz) δ 16.29, 19.82, 28.60 (CH3),
19.52, 27.87, 31.48, 32.74, 39.81, 40.34, 62.51 (CH2), 119.07 (CH),
34.97, 127.07, 136.94, 139.90 (C); MS m/ z (rel int) 236 (M+, 2),
191 (M+ - C2H5O, 2), 137 (M+ - C6H11O, 65), 95 (C7H11+, 100),
81 (C6H9+, 72), 67 (C5H7+, 28), 55 (27), 41 (64).
(E,E)-4,8,12-Tr im eth yl-3,7,11-tr id eca tr ien -1-ol (5). To a
solution of amide 4a (280 mg, 1.01 mmol) in anhyd THF (2 mL)
was added dropwise (15 min) a 1 M solution of LiBEt3H
(superhydride) in THF (3.6 mL) at -78 °C under argon. After
stirring for 7 h at -78 °C the reaction was allowed to warm,
water (5 mL) was added, and the mixture was extracted with
t-BuOMe (3 × 20 mL). The combined organic layers were dried
over anhyd Na2SO4 and concentrated to dryness, yielding a
residue which, after silica gel purification, afforded 5 (178 mg,
74.7%, hexane:t-BuOMe 85:15) (lit.12c): tR 30.98; IR 3343, 1047
1
(OH), 3050, 1670 (CHdC) cm-1; H NMR (300 MHz) δ 1.60 (s,
6H), 1.65 (s, 3H), 1.68 (s, 3H), 2.29 (br q, 7.3, 2H), 3.61 (t, 7.3,
2H), 5.06-5.17 (m, 3H); 13C NMR (75 MHz) δ 15.99, 16.18, 17.64,
25.65 (CH3), 26.47, 26.72, 31.49, 39.68, 39.77, 62.41 (CH2),
119.86, 123.97, 124.33 (CH), 131.27, 135.25, 138.84 (C); MS m/ z
(rel int) 236 (M+, 0.4), 167 (M+ - C5H9, 1), 136 (6), 123 (C9H15
+,
9), 95 (C7H11+, 9), 93 (9), 81 (C6H9+, 33), 69 (C5H9+, 100), 67
(C5H7+, 15), 41 (60).
4-(2′,6′,6′-Tr im eth ylcycloh ex-1′-en yl)bu tan -2-on e (12). Ke-
tone 12 was prepared from â-ionone (11) by either catalytic
hydrogenation (Raney-Ni/MeOH)29 or reduction under phase
transfer catalysis (Na2S2O4, Adogen 464)30 or free-radical reduc-
tion (Bu3SnH, cat. AIBN),28,31 the last method being the most
effective (91% yield; purity of 12: 98%). Spectral data of 12 (IR,
1H NMR, 13C NMR, MS) are according to that reported in the
literature.12c,28,32
(Z)-4-Meth yl-6-(2′,6′,6′-tr im eth ylcycloh ex-1′-en yl)-3-h exen -
1-ol (15b). (Z)-amide 14b (200 mg, 0.72 mmol) was treated with
superhydride (1.5 mL) for 5 h, under the same conditions
described for preparing alcohol 15a , to yield 15b (135 mg, 80%,
hexane:t-BuOMe 8:2) (lit.12c): tR 30.80; IR 3325, 1048 (OH) cm-1
;
1H NMR (400 MHz) δ 1.00 (s, 6H), 1.63 (s, 3H), 1.77 (s, 3H),
1.90 (t, 6.3, 2H), 1.98-2.12 (m, 4H), 2.29 (br q, 7.3, 6.5, 2H),
3.61 (t, 6.5, 2H), 5.09 (br t, 7.3, 1H); 13C NMR (100 MHz) δ 19.86,
23.44, 28.61 (CH3), 19.49, 27.23, 31.46, 32.67, 32.74, 39.77, 62.62
(CH2), 120.10 (CH), 34.92, 127.23, 136.91, 139.67 (C); MS m/ z
(rel int) 236 (M+, 2), 221 (M+ - CH3, 1), 203 (M+ - CH3 - H2O,
1), 191 (2), 137 (75), 95 (100), 81 (76), 67 (29), 55 (33), 41 (69).
Cycliza tion of 5, 15a , 15b w ith ClSO3H or H2SO4. Gen -
er a l P r oced u r e. To a solution of 99% ClSO3H (0.2 mL, 1.99
mmol) or 98% H2SO4 (0.3 mL, 5.49 mmol) in 1-nitropropane (1-2
mL) was added dropwise (1-7 min) a solution of the alcohol (80
mg, 0.34 mmol) in 1-nitropropane (2 mL) at -78 °C under argon.
After stirring for 6-25 min a saturated NaHCO3 solution (1-2
mL) was injected, and then further portions of solid NaHCO3
were added. The mixture was extracted with t-BuOMe (3 × 5
mL), and the combined organic layers were dried over anhyd
Na2SO4 and concentrated to dryness to yield a crude product
3-Meth yl-5-(2′,6′,6′-tr im eth ylcycloh ex-1′-en yl)-1-p en ten -
3-ol (13). To a 1 M solution of vinylmagnesium bromide in THF
(6.3 mL) was added dropwise (20 min) a solution of 12 (925 mg,
98% purity, 4.61 mmol) in anhyd THF (2 mL) at 10 °C under
argon. After stirring for 20 min at 10 °C and a further 30 min
at rt, a saturated NH4Cl solution (30 mL) was added at 0 °C
and the resulting mixture extracted with t-BuOMe (3 × 20 mL).
The extract was washed with 10% NaHCO3 solution and brine,
dried over anhyd Na2SO4, and concentrated to yield 13 (985 mg,
96.3%) (lit.16): tR 25.02; IR 3416, 1109 (tert OH), 3085, 1640,
997, 920 (CHdCH2) cm-1 1H NMR (300 MHz) δ 0.96 (s, 6H),
;
1.28 (s, 3H), 1.56 (s, 3H), 1.87 (br t, 6.2, 2H), 5.06 (dd, 10.7, 1.3,
1H), 5.21 (dd, 17.4, 1.3, 1H), 5.93 (dd, 17.4, 10.7, 1H); 13C NMR
(75 MHz) δ 19.74, 27.49, 28.61 (CH3), 19.48, 22.69, 32.73, 39.83,
42.30, 111.72 (CH2), 144.91 (CH), 35.06, 73.53, 127.01, 136.59
(C); MS m/ z (rel int) 222 (M+, 2), 204 (M+ - H2O, 8), 189 (M+
- CH3 - H2O, 18), 147 (10), 137 (M+ - C5H9O, 8), 133 (25), 123
(C9H15+, 40), 121 (41), 107 (31), 95 (C7H11+, 100), 93 (53), 81 (61),
79 (46), 71 (44), 55 (60), 43 (92), 41 (94).
1
which was studied directly by GC-MS and H NMR. Identifica-
tion of compounds 1, 2, and 6-10 was effected by comparison
of their MS data with those of authentic samples.27 The product
mixture distribution is presented in Table 1. Retention times
(min) are: 1 (30.93), 2 (29.79), 6 (29.89), 7 (30.02), 8 (30.78), 9
(29.54), 10 (27.80).
Rea ction of 13 w ith N,N-Dim eth ylfor m a m id e Dim eth yl
Aceta l. Alcohol 13 (950 mg, 4.28 mmol) was treated with
DMFDMA (3.06 g, 25.71 mmol) in xylene (10 mL) under the
same conditions described for 3 to yield a residue (1.13 g) which,
after silica gel column chromatography, afforded (E)-amide 14a
(594 mg, 50.1%, hexane:Et2O 1:1, 4:6) and (Z)-amide 14b (365
mg, 30.9%, hexane:Et2O 1:1).
Ack n ow led gm en t. We wish to thank Destilaciones
Garc´ıa de la Fuente (Granada, Spain) for supporting
this research.
Su p p or tin g In for m a tion Ava ila ble: Spectral assign-
ments and copies of 1H NMR and 13C NMR spectra of
compounds 4a , 4b, 5, 12-15 (18 pages). 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.
(E)-4-Meth yl-6-(2′,6′,6′-tr im eth ylcycloh ex-1′-en yl)-3-h ex-
en oic a cid N,N-d im eth yla m id e (14a ): tR 40.95; IR 1649
(29) Ohloff, G.; Schade, G. Angew. Chem. 1962, 74, 944.
(30) Camps, F.; Coll, J .; Guitart, J . Tetrahedron 1986, 42, 4603-
4609.
(31) Wolf, H. R.; Zink, M. P. Helv. Chim. Acta 1973, 56, 1062-1066.
(32) Contento, M.; Savoia, D.; Claudio, T.; Umani-Ronchi, A. Syn-
thesis 1979, 1, 30-32.
J O951908O