1052
LETTERS
SYNLETT
-1 1
cm ; H-NMR (250 MHz, CDCl ) δ 7.84 (d, 1H, J = 8.2 Hz, Ar-
3
H), 7.57 (d, 1H, J = 7.5 Hz, Ar-H), 7.37-7.23 (m, 2H, Ar-H), 7.18-
7.05 (m, 2H, Ar-H), 6.84-6.72 (m, 2H, Ar-H), 5.03 (d, 1H, J = 5.2
Hz, H ), 4.55 (dd, 1H, J = 4.4 and 12.1 Hz, OCH ), 4.40 (dd,
13b
2
1H, J = 3.2 Hz and 12.1 Hz, 1H, OCH ), 2.80 (s, 3H, COCH ),
2
3
13
2.45-2.40 (m, 1H, H ), 1.59 (s, 3H, CH ), 1.10 (s, 3H, CH ); C-
6a
3
3
NMR (62.9 MHz, CDCl ) δ 169.7 (CO), 153.9 (C), 138.7 (C),
3
134.5 (C), 129.1 (CH), 127.9 (CH), 125.0 (CH), 124.0 (C), 123.1
(C), 123.0 (CH), 120.9 (CH), 118.0 (CH), 117.1 (C), 116.0 (CH),
115.0 (CH), 78.6 (C), 66.0 (CH ), 40.4 (CH ), 33.3 (CH ), 28.0
2
13b
6a
+
(CH ), 27.4 (CH ), 23.0 (CH ); MS (IS) m/z 348 (MH ); Anal.
3
3
3
Calcd for C
H NO : C, 76.06, H, 6.09, 4.03; Found: C, 75.86;
22 21 3
H, 5.93; N, 3.89.
Physical data of ; brown oil, IR (film) 1693 cm . H-NMR
-1
1
5a
(250 MHz, CDCl ) δ 8.17 (d, 1H, J = 8.0 Hz, Ar-H), 7.58 (d, 1H J
3
= 7.0 Hz, Ar-H), 7.42-7.29 (m, 2H, Ar-H), 7.18-7.12 (m, 2H, Ar-
H), 6.92-6.82 (m, 2H, Ar-H), 4.43 (dd, 1H, J = 7.0 and 10.0 Hz,
OCH ), 4.23 (d, 1H, J = 12.0 Hz, H ), 4.14 (dd, 1H, J = 10.0 Hz
2
13b
and 12.0 Hz, OCH ), 2.63 (s, 3H, COCH ), 2.28-2.16 (m, 1H,
2
3
Scheme 2
13
H
), 1.49 (s, 3H, CH ), 1.37 (s, 3H, CH ); C-NMR (62.9 MHz,
3 3
6a
CDCl ) δ 169.9 (CO), 153.8 (C), 140.5 (C), 135.0 (C), 128.8 (C),
3
References and notes
128.0 (CH), 125.6 (CH), 124.7 (CH), 123.6 (C), 123.2 (CH),
121.1 (CH), 117.6 (CH), 117.1 (CH), 115.6 (CH), 114.6 (C), 77.0
1
(a) Tietze, L. F.; Bratz, M.; Machinek, R.; Kiedrowski, G. J. Org.
(C), 69.0 (CH ), 47.4 (CH ), 35.4 (CH ), 27.3 (CH ), 26.6
Chem. 1987, 52, 1638. (b) Tietze, L. F.; Denzer, H.; Holdgrün, X.;
Neumann, M. Angew. Chem., Int. Ed. Engl. 1987, 26, 1295. (c)
Tietze, L. F.; Geissler, H.; Fennen, J.; Brumby, T.; Brand, S.;
Schultz, G. J. Org. Chem. 1994, 59, 182. (d) Tietze, L. F.;
Bachmann, J.; Wichmann, J.; Burkhardt, O. Synthesis 1994, 1185.
(e) Buback M.; Abeln, J.; Hübsch, T.; Ott, C.; Tietze, L. F. Liebigs
Ann. 1995, 9. (f) Tietze, L. F. Chem. Rev. 1996, 96, 115. (g) Tietze,
L. F.; Kettschau G. Top. Curr. Chem. 1997, 189, 1. (h) Tietze, L.
F.; Kettschau, G.; Gewert, J. A.; Schuffenhauer, A. Curr. Org.
Chem. 1998, 2, 19.
2
13b
6a
3
+
(CH ), 18.3 (CH ); MS (IS) m/z 348 (MH ); Anal. Calcd for
3
3
C
H NO : C, 76.06, H, 6.09, 4.03; Found: C, 75.86; H, 5.83; N,
22 21 3
3.80.
8
Physical data of ; mp 225 °C (CH Cl /hexane); IR (KBr) 1706
8
2
2
-1 1
cm ; H-NMR (250 MHz, CDCl ) δ 7.88 (d, 1H, J = 8.2 Hz, Ar-
3
H), 7.61 (d, 1H, J = 7.8 Hz, Ar-H), 7.40-7.13 (m, 6H, Ar-H), 5.10-
4.90 (m, 1H, OCH ), 4.78 (d, 1H, J = 7.2 Hz, H ), 3.03-2.93 (m,
2
13b
1H, OCH ), 2.68 (s, 3H, COCH ), 2.65-2.55 (m, 1H, H ), 1.36 (s,
2
3
6a
13
3H, CH ), 1.18 (s, 9H, t-Bu), 0.72 (s, 3H, CH ); C-NMR (62.9
3
3
MHz, CDCl ,) δ 178.8 (CO), 168.7 (CO), 141.5 (C), 139.5 (C),
136.2 (C), 134.1 (C), 127.6 (CH), 126.8 (CH), 126.6 (CH), 125.1
(CH), 124.8 (CH), 123.7 (C), 123.0 (CH), 118.0 (CH), 114.9
2
3
Tietze L. F.; Schneider, C.; Grote, A. Chem. Eur. J. 1996, 2, 139.
3
Desimoni, G.; Faita, G.; Righetti, P.; Tacconi, G. Tetrahedron
1996, 52, 12009.
(CH), 114.8 (C), 78.6 (C), 46.5 (CH ), 44.7 (CH ), 41.1 (C), 35.9
2
6a
4
(a) Mérour, J.-Y.; Mérour, A. Synthesis 1994, 767. (b) Mérour, J.-
Y.; Chichereau, L.; Desarbre, E.; Gadonneix, P. Synthesis 1996,
516. (c) Mérour, J.-Y.; Mamai, A.; Malapel, B.; Gadonneix, P.
Tetrahedron 1997, 53, 987. (d) Désarbre, E.; Mérour, J.-Y.
Synthesis 1997, 73. (e) Mérour, J.-Y.; Piroëlle, S.; Joseph B.
Trends in Heterocyclic Chem. 1997, 5, 115.
(CH ), 29.3 (3C, CH ), 27.8 (CH ), 27.0 (CH ), 19.6 (CH ); MS
13b
3
3
3
3
+
(IS) m/z 431 (MH ); Anal. Calcd for C
H N O : C, 75.32, H,
27 30 2 3
7.02, N, 6.51; Found: C, 75.13; H, 6.88; N, 6.56.
-1
1
9
Physical data of : oil; IR (film) 1700 cm ; H-NMR (250 MHz,
9
CDCl ): δ 8.78 (s, 1H, Ar-H), 8.37, (d, 1H, J = 8.3 Hz, Ar-H),
3
8.27 (d, 1H, J = 8.3 Hz, Ar-H), 8.08 (d, 1H, J = 8.0 Hz, Ar-H),
5
6
7
Boger, D. L.; Corbett, W. L. J. Org. Chem. 1993, 58, 2068.
7.47-7.75 (m, 4H, Ar-H), 7.35 (t, 1H, J = 7.5 Hz, Ar-H), 2.24 (s,
1
Determined by H NMR
13
3H, COCH ), 2.13 (s, 3H, CH ), 1.73 (s, 3H, CH ); C-NMR
3
3
3
Typical procedure: A solution of compound 3a (132 mg, 0.38
mmol) in toluene (10 ml) in a sealed tube was heated at 140 °C for
3 days. After cooling, the solvent was removed in vacuo.
Purification of the crude residue by column chromatography on
silica gel (petroleum ether/EtOAc 8:2) gave 61 mg (46%) of 4a as
crystals and 20 mg (16%) of 5a as a brown oil.
(62.9 MHz, CDCl ): δ 172.1 (CO), 148.7 (C), 148.0 (C), 145.7
3
(CH), 139.2 (C), 129.9 (CH), 129.8 (C), 129.4 (CH), 128.6 (CH),
127.0 (CH), 125.1 (CH), 124.2 (CH), 121.4 (C), 120.7 (C), 118.8
(CH), 118.1 (C), 116.4 (CH), 80.9 (C), 27.3 (CH ), 26.8 (CH ),
3
3
+
24.6 (CH ); MS (IS) m/z 343 (MH ); Anal. Calcd for
3
C
H N O : C, 77.17, H, 5.30, N, 8.18; Found: C, 76.89; H,
22 18 2 2
Physical data of : mp 165 °C (EtOAc/hexane); IR (KBr) 1693
4a
5.06; N, 8.00.