3128 J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 16
Appendino et al.
column chromatography (7 g of silica gel, hexane-EtOAc, 3:7,
as eluant) to give 290 mg (73% from 4a ) of 5a as a white
powder: mp 104 °C; IR (KBr) 3300, 1730, 1460, 1320, 1240,
980 cm-1; MS (CI, isobutane) m/e 525 (M+ + H) (100); 1H NMR
(300 MHz, CDCl3) δ 7.56 (br s, H-1), 7.29 (m, PhCH2CO), 5.64
(d, J ) 5.4 Hz, H-7), 5.53 (br s, OH), 5.40 (d, J ) 10.5 Hz,
H-12), 4.02 (d, J ) 13.3 Hz, H-20a), 3.96 (d, J ) 13.3 Hz,
H-20b), 3.66 (d, J ) 14.7 Hz, PhCH2CO), 3.62 (d, J ) 14.7 Hz,
PhCH2CO), 3.20 (br s, H-8, H-10), 2.55 (br d, J ) 19.5 Hz,
H-5a), 2.46 (br d, J ) 19.5 Hz, H-5b), 2.07 (s, Ac), 1.76 (d, J )
1.6 Hz, H-19), 1.08 (s, H-16), 1.01 (s, H-17), 0.84 (d, J ) 6.4
Hz, H-18).
To avoid unnecessary manipulation of dangerous products,29
the crude diesters were directly used for the esterification with
Mem-homovanillic acid. When the procedure was tested on
both purified and crude diesters (compounds 5a ,b), no detri-
mental decrease of the yield was observed.
cm-1; MS (CI, isobutane) m/e 675 (M+ + H) (100); 1H NMR
(300 MHz, CDCl3) δ 8.03 (d, J ) 7.6 Hz, o-Bz), 7.59 (br s, H-1),
7.58 (t, J ) 7.6 Hz, p-Bz), 7.46 (t, J ) 7.6 Hz, m-Bz), 6.79 (br
d, J ) 8.0 Hz, 6-HMV), 6.77 (br s, 2-HMV), 6.72 (br d, J ) 8.0
Hz, 5-HMV), 5.66 (d, J ) 9.9 Hz, H-12), 5.61 (br s, H-7), 5.56
(br s, OH), 4.54 (d, J ) 12.4 Hz, H-20a), 4.47 (d, J ) 12.4 Hz,
H-20b), 3.91 (s, OMe), 3.55 (br s, HMV-CH2), 3.28 (br s, H-8),
3.22 (br s, H-10), 2.48 (d, J ) 19.0 Hz, H-5a), 2.33 (d, J ) 19.0
Hz, H-5b), 2.25 (m, H-11), 2.15 (s, Ac), 1, 78 (br s, H-19), 1.35
(s, H-16), 1.20 (s, H-17), 1.01 (d, J ) 5.1 Hz, H-14), 0.94 (d, J
) 6.6 Hz, H-18). Anal. (C38H42O11) C, H.
P h or bol 12-p-a zid op h en yla ceta te 13-a ceta te 20-h om o-
va n illa te (6c): mp 80 °C; IR (KBr) 3400, 2120, 1750, 1375,
1
1260, 1140, 980, 790 cm-1; H NMR (300 Mhz, CDCl3) δ 7.53
(br s, H-1), 7.24 (d, J ) 8.4 Hz, Ph), 6.98 (d, J ) 8.4 Hz, Ph),
6.79 (br d, J ) 8.0 Hz, 6-HMV), 6.77 (s, 2-HMV), 6.71 (d, J )
8.0 Hz, 5-HMV), 5.52 (br s, H-7), 5.44 (s, OH), 5.38 (d, J )
10.6 Hz, H-12), 4.49 (d, J ) 12.5 Hz, H-20a), 4.41 (d, J ) 12.5
Hz, H-20b), 3.86 (s, OMe), 3.56 (d, J ) 15.0 Hz, PhCH2CO),
3.52 (d, J ) 15.0 Hz, PhCH2CO), 3.37 (br d, HMV-CH2), 3.13
(br s, H-8, H-10), 2.39 (d, J ) 19.1 Hz, H-5a), 2.28 (d, J ) 19.1
Hz, H-5b), 2.09 (m, H-11), 2.08 (s, Ac), 1.76 (br s, H-19), 1.08
(s, H-16), 1.03 (s, H-17), 0.89 (d, J ) 5.1 Hz, H-14), 0.80 (d, J
) 6.6 Hz, H-18); HMRS (FAB+) m/e calcd for (M+ + 1)
C39H44N3O11 730.2976, found 730.2985; analytical HPLC (hex-
ane-EtOAc, 1:1) tR ) 14.6 min (96% pure).
(b) To a solution of crude phorbol 13-acetate 12-phenyl-
acetate (5a ) [2.70 g, corresponding to 1.70 g (3.24 mmol) of
pure diester on the basis of the extrapolated yield] in 70 mL
of dry CH2Cl2 were added Mem-homovanillic acid (1.74 g, 6.48
mmol, 2 equiv), DCC (1.33 g, 6.48 mmol, 2 equiv), and DMAP
(50 mg). After stirring for 1 h at room temperature, the
solution was diluted with ether (70 mL) and filtered. The
filtrate was washed with brine, dried (Na2SO4), and evapo-
rated. The residue was purified by column chromatography
(50 g of silica gel, hexane-EtOAc, 3:7, as eluant) to give 2.360
g (94%) of the 20-Mem-homovanillate as a white powder: mp
P h or bol 12-p-a zid oben zoa te 13-a ceta te 20-h om ova n il-
la te (6d ): mp 98 °C; IR (KBr) 3400, 2140, 1720, 1380, 1275,
1180, 1135, 1100 cm-1; MS (CI, isobutane) m/e 716 (M+ + H)
(100); 1H NMR (300 MHz, CDCl3) δ 8.01 (d, J ) 8.8 Hz, o-Bz),
7.59 (s, H-1), 7.08 (d, J ) 8.8 Hz, m-PH), 6.83 (br d, J ) 7.9
Hz, 6-HMV), 6.80 (br s, 2-HMV), 6.76 (br d, J ) 7.0 Hz,
5-HMV), 5.64 (d, J ) 10.2 Hz, H-12), 5.57 (br s, H-7), 5.53 (br
s, OH), 4.54 (d, J ) 12.5 Hz, H-20a), 4.47 (d, J ) 12.5 Hz,
H-20b), 3.90 (s, OMe), 3.40 (HMV-CH2), 3.25 (br s, H-8), 3.21
(br s, H-10), 2.48 (d, J ) 19.1 Hz, H-5a), 2.33 (d, J ) 19.1 Hz,
H-5b), 21.8 (m, H-11), 2.15 (s, Ac), 1.79 (br s, H-19), 1.34 (s,
H-16), 1.20 (s, H-17), 1.00 (d, J ) 5.2 Hz, H-14), 0.93 (d, J )
6.6 Hz, H-18); HMRS (FAB+) m/e calcd for (M+ + 1) C38H42N3O11
716.2819, found 716.2810; analytical HPLC (hexane-EtOAc,
1:1) tR ) 13.8 min (97% pure).
85 °C; IR (KBr) 3400, 1740, 1380, 1320, 1220, 1130, 990 cm-1
;
MS (CI, isobutane) m/e 777 (M+ + H) (100); 1H NMR (300 MHz,
CDCl3) δ 7.55 (s, H-1), 7.29 (m, PhCH2CO), 7.11 (br d, J ) 8.1
Hz, 6-HMV), 6.80 (br s, 2-HMV), 6.75 (d, J ) 8.1 Hz, 5-HMV),
5.63 (br s, H-7), 5.48 (br s, OH), 5.39 (d, J ) 10.4 Hz, H-12),
5.28 (s, 2H, Mem), 4.49 (d, J ) 12.4 Hz, H-20a), 4.46 (d, J )
12.4 Hz, H-20b), 3.85 (s, HMV-OMe), 3.84 (m, 2H, Mem), 3.69
(d, J ) 14.7 Hz, PhCH2CO), 3.65 (d, J ) 14.7 Hz, PhCH2CO),
3.55 (m, 2H, Mem), 3.55 (br s, HMV-CH2), 3.36 (s, Mem-OMe),
3.16 (br s, H-8, H-10), 2.40 (d, J ) 19.0 Hz, H-5a), 2.36 (d, J
) 19.0 Hz, H-5b), 2.09 (m, H-11), 2.07 (s, Ac), 1.76 (br s, H-19),
1.07 (s, H-16), 0.99 (s, H-17), 0.96 (d, J ) 5.4 Hz, H-14), 0.83
(d, J ) 6.4 Hz, H-18).
(c) To a solution of the Mem-homovanillate (1.33 g, 1.71
mmol) in dry THF (100 mL) was added SnCl4 (1.00 mL, 2.23
g, 8.6 mmol, 5 equiv) dropwise. During the addition, a white
precipitate was formed, which then dissolved as the reaction
proceeded. After stirring for 90 min under a nitrogen atmo-
sphere, the reaction mixture was worked up by the addition
of saturated NaHCO3 (ca. 25 mL) and extracted with EtOAc
(2 × 50 mL). After washing with brine, drying (Na2SO4), and
evaporation, the residue was purified by column chromatog-
raphy (25 g of silica gel, hexane-EtOAc, 7:3, as eluant) to give
1.57 g (76%) of 6a as a white powder: mp 75 °C; IR (KBr)
3420, 1740, 1390, 1275, 1150, 1040, 990 cm-1; MS (CI,
isobutane) m/e 689 (M+ + H) (100); 1H NMR (300 MHz, CDCl3)
δ 7.53 (s, H-1), 7.27 (m, PhCH2CO), 6.79 (br d, J ) 8.0 Hz,
6-HMV), 6.77 (br s, 2-HMV), 6.72 (br d, J ) 8.0 Hz, 5-HMV),
5.57 (br s, OH), 5.53 (br s, H-7), 5.43 (br s, OH), 5.38 (d, J )
10.6 Hz, H-12), 4.51 (br d, J ) 12.8 Hz, H-20a), 4.42 (br d, J
) 12.8 Hz, H-20b), 3.87 (OMe), 3.64 (d, J ) 14.7 Hz,
PhCH2CO), 3.62 (d, J ) 14.7 Hz, PhCH2CO), 3.50 (br s, HMV-
CH2), 3.12 (br s, H-8, H-10), 2.41 (br d, J ) 19.1 Hz, H-5a),
2.27 (br d, J ) 19.1 Hz, H-5b), 2.07 (s, Ac), 2.07 (m, H-11),
1.76 (br s, H-19), 1.05 (s, H-16), 0.99 (s, H-17), 0.88 (d, J ) 5.1
Hz, H-14), 0.81 (d, J ) 6.2 Hz, H-18); 13C NMR (75 MHz,
CDCl3) δ 160.5 (d, C-1), 135.3 (s, C-2), 208.1 (s, C-3), 73.5 (s,
C-4), 38.7 (t, C-5), 132.7 (s, C-6), 131.9 (d, C-7), 39.2 (d, C-8),
78.0 (s, C-9), 56.1 (d, C-10), 42.8 (d, C-11), 77.4 (d, C-12), 65.4
(d, C-13), 36.0 (d, C-14), 25.8 (s, C-15), 23.5 (q, C-16), 16.3 (q,
C-17), 14.2 (q, C-18), 10.0 (q, C-19), 68.7 (t, C-20), 171.4 (s,
HMV CO), 41.0 (t, HMV-CH2), 125.6 (s, 1-HMV), 111.7 (d,
2-HMV), 146.4 (s, 3-HMV), 144.7 (s, 4-HMV), 114.3 (d, 5-HMV),
122.1 (d, 6-HMV), 173.6 (s, PhCH2CO), 41.7 (t, PhCH2CO),
134.0 (s, i-Ph), 129.0 (d, o-Ph), 128.5 (d, m-Ph), 127.0 (d, p-Ph),
171.2 (s, Ac), 21.0 (q, Ac), 56.0 (q, OMe). Anal. (C39H44O11) C,
H.
P h or bol 12-cycloh exyla ceta te 13-a ceta te 20-h om ova -
n illa te (6e): mp 70 °C; IR (KBr) 3416, 1728, 1516, 1450, 1377,
1253, 1149, 987 cm-1; MS (CI, isobutane) m/e 695 (M+ + H)
1
(100); H NMR (300 MHz, CDCl3) δ 7.57 (br s, H-1), 6.82 (br
d, J ) 8.0 Hz, 6-HMV), 6.79 (br s, 2-HMV), 6.73 (br d, J ) 8.0
Hz, 5-HMV), 5.57 (br s, H-7), 5.40 (d, J ) 10.4 Hz, H-12), 4.49
(d, J ) 12.5 Hz, H-20a), 4.45 (d, J ) 12.5 Hz, H-20b), 3.88 (s,
OMe), 3.70 (d, J ) 14.5 Hz, HMV-CH2), 3.57 (d, J ) 14.5 Hz,
HMV-CH2), 3.15 (br s, H-8, H-10), 2.43 (d, J ) 19.0 Hz, H-5a),
2.30 (d, J ) 19.0 Hz, H-5b), 2.17 (br s, C6H11-CH2CO), 2.09
(m, H-11), 2.09 (s, Ac), 1.78 (br s, H-19), 1.70-1.30 (m, C6H11
-
CH2CO), 1.21 (s, H-16), 1.17 (s, H-17), 0.93 (d, J ) 5.2 Hz,
H-14), 0.83 (d, J ) 6.6 Hz, H-18); 13C NMR (75 MHz, CDCl3)
δ 160.7 (d, C-1), 135.2 (s, C-2), 208.5 (s, C-3), 73.5 (s, C-4),
38.7 (t, C-5), 132.8 (s, C-6), 132.0 (d, C-7), 39.2 (d, C-8), 78.0
(s, C-9), 56.0 (s, C-10), 42.7 (d, C-11), 76.2 (d, C-12), 65.5 (s,
C-13), 35.9 (d, C-14), 25.4 (s, C-15), 23.6 (q, C-16), 16.7 (q,
C-17), 14.3 (q, C-18), 10.0 (q, C-19), 68.8 (t, C-20), 171.0 (s,
HMV-CO), 41.0 (t, HMV-CH2), 152.6 (s, 1-HMV), 111.7 (d,
2-HMV), 144.2 (s, 3-HMV), 146.5 (s, 4-HMV), 114.3 (d, 5-HMV),
122.1 (d, 6-HMV), 56.0 (q, OMe), 172.9 (s, C6H11-CH2CO), 42.4
(t, C6H11-CH2CO), 35.2 (d, C6H11-CH2CO), 32.9 (t, C6H11-CH2-
CO), 26.0 (t, C6H11-CH2CO), 26.0 (t, C6H11-CH2CO), 173.7 (s,
Ac), 21.0 (q, Ac); HMRS (FAB+) m/e calcd for (M+ + 1)
C39H51O11 695.3431, found 695.3437; analytical HPLC (hex-
ane-EtOAc, 1:1) tR ) 15.2 min (99% pure).
P h or bol 12-cycloh exa n eca r boxyla te 13-a ceta te 20-h o-
m ova n illa te (6f): mp 68 °C; IR (KBr) 3400, 1725, 1630, 1516,
1377, 1273, 1263, 1130, 1034 cm-1; MS (CI, isobutane) m/e 681
1
(M+ + H) (100); H NMR (300 MHz, CDCl3) δ 7.56 (s, H-1),
6.81 (d, J ) 8.0 Hz, 6-HMV), 6.78 (br s, 2-HMV), 6.73 (br d, J
) 8.0 Hz, 5-HMV), 5.56 (br s, H-7), 5.53 (br s, OH), 5.49 (br s,
OH), 5.37 (d, J ) 10.6 Hz, H-12), 4.49 (d, J ) 12.7 Hz, H-20a),
4.45 (d, J ) 12.7 Hz, H-20b), 3.88 (s, OMe), 3.73 (d, J ) 15.0
Hz, HMV-CH2), 3.53 (d, J ) 15.0 Hz, HMV-CH2), 3.15 (br s,
H-8, H-10), 2.43 (d, J ) 19.0 Hz, H-5a), 2.33 (m, C6H11-CO),
P h or bol 12-ben zoa te 13-a ceta te 20-h om ova n illa te (6b):
mp 75 °C; IR (KBr) 3390, 1720, 1375, 1270, 1150, 785, 710