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J. D. Buynak et al. / Tetrahedron 56 (2000) 5709±5718
of AB q, J13 Hz), 4.67 (1H, d, B of AB q, J13 Hz), 3.50
(1H, d, A of AB q, J18 Hz), 3.32 (1H, d, B of AB q,
J18 Hz), 1.98 (s, 3H), 0.31 (9H, s) 13C NMR (CDCl3) d
170.1 (s), 161.0 (s), 160.1 (s), 139.9 (s), 139.3 (s), 138.2 (s),
129.0, 128.5, 128.7, 127.9, 127.6, 127.1, (s), 124.2 (s), 112.1
(d), 80.7 (d), 63.8 (t), 59.5 (d), 27.6 (t), 20.5 (q), -6.3 (q).
column chromatography using 10±20% EtOAc in hexane
provided slightly brown solid (0.23 g, 55% yield): mp 728C;
1
IR (CHCl3) 3065, 2931 1765, 1376, 1233 cm21; H NMR
(CDCl3) d 7.45±7.28 (10H, m), 7.20 (1H, s), 6.98 (1H, s),
5.23 (1H, s), 4.97 (1H, d, J13H), 4.73 (1H, d, J13H),
3.55 (1H, d, J18H), 3.34 (1H, d, J18H), 2.01 (3H, s). 13C
NMR (CDCl3) d 170.3, 160.6, 156.0, 144.1, 139.1, 138.9,
128.4, 128.1, 127.7, 127.0, 126.9, 124.3, 110.0, 79.8, 63.0,
57.5, 27.2, 20.5. HRMS (FAB) calcd for C24H20BrNO5S
m/z: (MH1) 514.0324, found: 514.0328.
Benzhydryl 3-(acetoxymethyl)-7-[(E)-(trimethylstannyl)-
methylidene]ceph-2-em-4-carboxylate (23) IR (neat)
1
3002, 1745, 1300 cm21; H NMR (CDCl3) d 7.36±7.26
(10H, m), 7.16 (1H, s), 6.89 (1H, s), 6.66 (1H, s), 6.48
(1H, s), 5.19 (1H, s), 4.59 (1H, s), 1.93 (s, 3H), 0.31 (9H,
s) 13C NMR (CDCl3) d 170.0, 162.1, 161.1, 156.6, 139.0,
138.3, 137.8, 129.2, 128.9, 128.7, 127.6, 127.1, 124.8,
124.0, 89.9, 70.2, 60.2, 28.6, 20.8, 26.3.
Benzhydryl 7-[(Z)-prop-20-enylidene]cephalosporanate
1,1-dioxide (30). Mp 698C; IR (CHCl3) 3005, 2950, 1788,
1275, 1130 cm21; 1H NMR (CDCl3) d 7.45±7.25 (10H, m),
7.00 (1H, d, J11 Hz), 6.97 (1H, s), 6.55±6.44 (1H, m),
5.84±5.77 (2H, m), 5.27 (1H, s), 4.99 (1H, d, A of AB q,
J13 Hz), 4.67 (1H, d, B of ABq, J13 Hz), 3.99 (1H, d, A
of AB q, J18 Hz), 3.76 (d, 1H, B of ABq, J18 Hz), 2.03
(s, 3H). 13C NMR (CDCl3) d 170.4, 160.8, 157.8, 139.2,
139.0, 137.6, 130.2, 128.2, 127.8, 127.7, 127.4, 127.3,
126.8, 122.9, 122.3, 80.0, 63.1, 58.1, 50.1, 20.6. HRMS
(FAB) calcd for C26H23NO7S m/z: (MLi1) 500.1355,
found: 500.1346.
Benzhydryl 7-[(E)-(20-thiophenyl)methylidene]cephalo-
sporanate 1,1-dioxide (24). Mp 88±918C; IR (CHCl3)
2988, 2220, 1775, 1604, 1336, 1230 cm21 1H NMR
;
(CDCl3) d 7.99 (1H, d, J6.1 Hz), 7.81 (1H, m), 7.57±
7.12 (11H, m), 6.99 (1H, s), 6.77 (1H, s), 5.22 (1H, s),
4.89 (1H, d, A of AB q, J13 Hz), 4.61 (1H, d, B of AB
q, J13 Hz), 3.81 (1H, d, A of AB q, J18 Hz), 3.62 (1H, d,
B of AB q, J18 Hz), 1.92 (s, 3H). 13C NMR (CDCl3) d
170.4, 160.2, 158.3, 151.7, 149.7, 138.2, 136.8, 130.8, 128.0
128.3, 127.6, 127.0, 126.4, 125.7, 124.6, 123.6, 80.4, 69.4,
62.04, 51.3, 20.5.
Benzhydryl 7-[(Z)-30-phenylprop-20-ynlidene]cephalo-
sporanate 1,1-dioxide (31). Mp 1048C; IR (CHCl3) 2988,
1
2220, 1775, 1336, cm21; H NMR (CDCl3) d 7.61±7.24
(15H, m), 7.11 (1H, s), 7.00 (1H, s), 5.21 (1H, s), 4.96
(1H, d, A of AB q, J14 Hz), 4.66 (1H, d, B of AB q,
J14 Hz), 4.00 (1H, d, A of AB q, J18 Hz), 3.77 (d,
1H, B of AB q, J18 Hz), 1.99 (s, 3H). 13C NMR
(CDCl3) d 170.4, 160.6, 157.1, 138.8, 137.7, 132.5, 130.1,
128.7, 128.4, 128.1, 127.9, 127.7, 127.3, 126.8, 126.6,
123.9, 122.2, 121.4, 114.4, 100.9, 88.8, 80.1, 70.7, 62.2,
50.9, 20.6. HRMS (FAB) calcd for C32H25N2O7S m/z:
(MLi1) 574.1512, found: 574.1504.
Benzhydryl
sporanate 1,1-dioxide (25). Mp 107±1108C; 1H NMR
(CDCl3)
7-[(E)-(20-thiazolyl)methylidene]cephalo-
d
8.04 (1H, d, J3.1 Hz), 7.61 (1H, d,
J3.1 Hz), 7.45±7.25 (10H, m), 6.99 (1H, s), 5.14 (1H,
s), 4.90 (1H, d, A of AB q, J14 Hz), 4.67 (1H, d, B of
AB q, J14 Hz), 3.93 (1H, d, A of AB q, J18 Hz), 3.69
(1H, d, B of AB q, J18 Hz), 2.00 (s, 3H). 13C NMR
(CDCl3) d 170.4, 161.3, 159.8, 151.2, 149.3, 139.4, 137.2,
130.4, 129.0, 128.7, 127.9, 127.6, 127.1, 126.4 124.2, 81.0,
63.9, 59.7, 50.2, 20.1. HRMS (FAB) calcd for
C27H22N2O7S2 m/z: (MLi1) 557.1028, found: 557.1024.
Benzhydryl 7-[(Z)-(trimethylstannyl)methylidene]ce-
phalosporanate (32). (D-3,4 isomer): IR (neat) 2996,
1
2950, 1765, 1325, 1208 cm21; H NMR (CDCl3) d 7.47±
Benzhydryl
7-[(E)-(20,40-dinitrophenyl)methylidene]-
cephalosporanate 1,1-dioxide (26). Mp 198±2018C; IR
7.22 (11H, m), 6.99 (1H, s), 5.11 (1H, s), 4.88 (1H, d, A of
AB q, J14 Hz), 4.69 (1H, d, B of AB q, J14 Hz), 3.51
(1H, d, A of AB q, J18 Hz), 3.33 (1H, d, B of AB q,
J18 Hz), 1.99 (s, 3H), 0.31 (9H, s) 13C NMR (CDCl3) d
170.1, 161.0, 160.1, 141.1, 139.3, 138.2, 129.9, 129.5,
128.7, 127.1, 126.6, 126, 123.2, 109.1, 80.7, 63.8, 60.1,
26.6, 20.9, 26.6.
1
(CHCl3) 3005, 2980, 1774, 1562, 1345, 1266 cm21; H
NMR (CDCl3) d 8.95 (1H, d, J1.68 Hz), 8.50 (1H, d,
J8.4 Hz), 7.92 (1H, d, J8.4 Hz), 7.41±7.24 (10H, m),
6.93 (1H, s), 5.18 (1H, s), 4.99 (1H, d, A of AB q,
J13 Hz), 4.64 (1H, d, B of AB q, J13 Hz), 3.93 (1H,
d, A of AB q, J18 Hz), 3.76 (d, 1H, B of AB q, J
18 Hz), 1.95 (s, 3H). 13C NMR (CDCl3) d 170.4, 161.5,
157.1, 138.8, 137.7, 132.5, 130.1, 129.6, 128.7, 128.4,
128.1, 127.7, 127.3, 127.8, 126.6, 123.9, 123.2, 121.4,
113.4, 99.9, 88.8, 80.1, 70.7, 62.2, 50.9, 21.1.
Benzhydryl
7-[(Z)-(20-thiazolyl)methylidene]cephalo-
sporanate 1,1-dioxide (33). Mp 99±1038C; IR (CHCl3)
1
3016, 2950, 1764, 1296, 1210 cm21; H NMR (CDCl3) d
7.94 (1H, d, J3.3 Hz), 7.48±7.25 (11H, m), 6.97 (1H, s),
5.92 (1H, s), 5.05 (1H, d, A of AB q, J14 Hz), 4.73 (1H, d,
B of AB q, J14 Hz), 4.13 (1H, d, A of AB q, J18 Hz),
3.76 (1H, d, B of AB q, J18 Hz), 1.98 (s, 3H). 13C NMR
(CDCl3) d 170.0, 159.7, 158.6, 158.4, 145.4, 138.7, 131.2,
128.4, 128.1, 128.0, 127.3, 127.1, 126.9 125.9, 125.7, 123.7,
122.6, 80.2, 72.2, 61.5, 52.4, 20.3. HRMS (FAB) calcd for
C27H22N2O7S2 m/z: (MLi1) 557.1028, found: 557.1032.
Benzhydryl 7-[(Z)-Bromomethylidene]cephalosporanate
(27). A solution of 7-[dibromomethylene]cephalosporanate
14 (0.5 g, 0.84 mmol) in anhydrous THF was cooled to
21008C and a solution of isopropylmagnesium chloride
(2.0 M solution in THF, 0.42 mL, 0.84 mmol) was added
dropwise over a period of 15 min. After 10 min at
21008C acetic acid (0.1 g, 1.6 mmol) was added via syringe
and stirring continued for another 30 min. Saturated NH4Cl
solution was then added and the separated THF layer was
dried over Na2SO4. Removal of volatiles and puri®cation by
Benzhydryl 7-[(Z)-(50-nitro-20-pyridyl)methylidene]ce-
phalosporanate 1,1-dioxide (34). Mp 149±1538C; IR
1
(CHCl3) 3046, 2966, 1786, 1378, 1228 cm21; H NMR