1132
S. P. Chavan et al.
LETTER
IR (CHCl3): 3020, 2400, 1731, 757 cm–1. 1H NMR (200
(21) Yasuaki, O. Jpn. KoKai Tokkyo Koho, JP 63,08,315, 1988;
Chem. Abstr. 1988, 109, 196909qP.
(22) Kyotaro, H. Jpn. KoKai Tokkyo Koho, JP 62,175,417, 1988;
Chem. Abstr. 1988, 108, 62465nP.
(23) (a) Kursanov, D. N.; Parnes, Z. N.; Loim, N. M. Synthesis
1974, 633. (b) Parnes, Z. N.; Bolestova, G. I.; Belenkiy, L.
I.; Kursanov, D. N. Izv. Akad. Nauk SSSR, Ser. Khim. 1973,
1918; Chem. Abstr. 1974, 80, 14800.
(24) Menon, R. B. Ph. D. Thesis; University of Pune:
Maharashtra, India, 1987.
MHz, CDCl3 + CCl4): d = 8.53 (s, 1 H), 7.58 (d, J = 8.3 Hz,
2 H), 7.25 (d, J = 8.3 Hz, 2 H), 3.74 (dd, J = 7.8, 6.4 Hz, 1
H), 3.61 (s, 3 H), 3.56 (d, J = 15.6 Hz, 1 H), 3.21 (d, J = 15.6
Hz, 1 H), 2.37 (s, 3 H), 2.19 (t, J = 7.8 Hz, 2 H), 1.76–1.84
(m, 1 H), 1.68 (s, 3 H), 1.46 (s, 3 H), 1.20–1.61 (m, 5 H).
13C NMR (50 MHz, CDCl3 + CCl4): d = 173.6 (s), 155.7 (s),
143.9 (s), 135.4 (s), 129.3 (d), 128.1 (d), 51.2 (q), 49.7 (s),
45.1 (d), 33.6 (t), 32.2 (q), 31.0 (q), 28.9 (t), 26.1 (t), 25.6 (t),
24.4 (t), 21.3 (q). MS (ESI, solvent: MeCN + H2O +
CH3COONH4): m/z = 445.04 [M + 1]. HRMS (ESI+ mode):
m/z calcd for C19H29N2O4S3 [M + H]+: 445.1289; found:
445.1271.
(25) Data for Selected Compounds. (a) Methyl 4-(4-
methoxycarbonyl-butyl)-2,2-dimethyl-5-oxo-(1,3)-
dithiane-4-carboxylate (8c): molecular formula:
C14H22O5S2; yield 70%; viscous liquid. IR (CHCl3): 3021,
2953, 2925, 1748, 1713, 1439, 1160, 765 cm–1. 1H NMR
(200 MHz, CDCl3 + CCl4): d = 3.76 (d, J = 18.6 Hz, 1 H),
3.75 (s, 3 H), 3.60 (s, 3 H), 3.30 (d, J = 18.6 Hz, 1 H), 2.24
(t, J = 7.3 Hz, 2 H), 1.64–1.85 (m, 5 H), 1.72 (s, 3 H), 1.64
(s, 3 H), 1.17–1.27 (m, 2 H). 13C NMR (125 MHz, CDCl3 +
CCl4): d = 197.1 (s), 173.5 (s), 170.0 (s), 61.7 (s), 53.1 (q),
51.4 (q), 50.6 (s), 36.6 (t), 33.6 (t), 32.7 (q), 32.6 (t), 32.2 (q),
25.0 (t), 24.2 (t). MS (EI): m/z (%) = 334 (26), 303 (6), 270
(15), 260 (10), 237 (2), 228 (18), 212 (14), 197 (27), 180
(36), 169 (23), 159 (27), 155 (39), 141 (32), 127 (81), 123
(68), 115 (100), 99 (94), 87 (51), 73 (76), 59 (25). HRMS
(ESI+ mode): m/z calcd for C14H22O5NaS2 [M + Na]+:
357.0806; found: 357.0811. (b) Methyl 5-[2,2-dimethyl-5-
oxo-(1,3)-dithian-4-yl]pentanoate (9c): molecular formula:
C12H20O3S2; yield 81%; viscous liquid. IR (CHCl3):
3020, 1732, 1711, 772, 744 cm–1. 1H NMR (200 MHz,
CDCl3 + CCl4): d = 3.98 (dd, J = 6.8, 5.9 Hz, 1 H), 3.64 (s,
3 H), 3.63 (d, J = 16.6 Hz, 1 H), 3.25 (d, J = 16.6 Hz, 1 H),
2.29 (t, J = 7.3 Hz, 2 H), 1.76–1.92 (m, 1 H), 1.84 (s, 3 H),
(26) General Procedure for Decomposition of Tosylhydra-
zones to Olefins.
A mixture of tosylhydrazone (1 mmol) and NaOH (2 mmol)
in i-PrOH (10 mL) was refluxed for 2–3 h. The reaction was
monitored by TLC, and after the completion of the reaction,
i-PrOH was removed under vacuum and the residue was
extracted with Et2O. The ether layer was dried over anhyd
Na2SO4 and filtered. Then Et2O was removed under vacuum
and the residue was purified by column chromatography.
(27) Typical Procedure for Entry 3 in Table 2 (3c and 4c). The
mixture of tosylhydrazone 2c (200 mg, 0.450 mmol) and
NaOH (40 mg, 2 mmol) in i-PrOH (10 mL) was refluxed for
2–3 h. The reaction was monitored by TLC and after the
completion of the reaction, i-PrOH was removed under
vacuum and H2O was added to the reaction mixture. Then
aqueous layer was washed with Et2O and then acidified with
dilute HCl. Finally, the aqueous layer was extracted with
Et2O (3 × 15 mL). The ether layer was dried over anhyd
Na2SO4, filtered and Et2O was removed under vacuum. The
residue was purified by column chromatography to give 93
mg (84%) of pure product (3c and 4c).
1.56–1.71 (m, 2 H), 1.66 (s, 3 H), 1.34–1.49 (m, 3 H). 13
C
NMR (125 MHz, CDCl3 + CCl4): d = 204.0 (s), 173.6 (s),
51.4 (q), 50.4 (s), 47.1 (d), 37.1 (t), 33.7 (t), 32.8 (q), 31.9
(q), 27.2 (t), 26.6 (t), 24.7 (t). MS (EI): m/z (%) = 276 (57),
262 (3), 243 (13), 225 (6), 211 (8), 202 (11), 179 (8), 170
(100), 153 (24), 142 (28), 127 (36), 111 (16), 93 (21), 73
(68), 56 (11). HRMS (ESI+ mode): m/z calcd for
Data for 5-(2,2-dimethyl-6H-[1,3]dithiin-4-yl)pentanoic
acid(3c): molecular formula: C11H18O2S2; yield 84%;
viscous liquid. IR (CHCl3): 2985, 1709, 1216, 1167 cm–1. 1H
NMR (200 MHz, CDCl3 + CCl4): d = 10.06 (br s, 1 H), 5.75
(t, J = 4.4 Hz, 1 H), 3.44 (d, J = 4.4 Hz, 2 H), 2.34 (t, J = 7.3
Hz, 2 H), 2.20 (t, J = 6.4 Hz, 2 H), 1.67 (s, 6 H), 1.42–1.74
(m, 4 H). 13C NMR (50 MHz, CDCl3 + CCl4): d = 179.2 (s),
136.5 (s), 111.4 (d), 47.3 (s), 38.2 (t), 33.8 (t), 31.0 (q), 28.3
(t), 26.4 (t), 23.7 (t). MS (ESI, solvent: MeCN + H2O +
CH3COONH4): m/z = 263.05 [M + NH3], 245.05 [M – 1].
C12H20O3NaS2 [M + Na]+: 299.0752; found: 299.0742.
(c) 5-[5-(p-Toluenesulfonyl)hydrazono-2,2-dimethyl-(1,3)-
dithian-4-yl]pentanoic acid methyl ester (2c): molecular
formula: C19H28O4N2S3; yield 87%; white solid, mp 120 °C.
Synlett 2005, No. 7, 1129–1132 © Thieme Stuttgart · New York