M. Hainrichson et al. / Bioorg. Med. Chem. 13 (2005) 5797–5807
5805
(100 mL). The organic layer was dried over Na2SO4.
The solvent was removed, and the residue was purified
by column chromatography on silica gel (hexane/EtOAc
3:1) to give 13 (1.2 g, 34.3%) as a syrup. 1H NMR
(300 MHz, CDCl3) d: 2.02 (s, 3H, OCOMe), 2.05 (s,
3H, OCOMe), 2.12 (s, 3H, OCOMe), 2.29 (s, 3H, MeS-
Tol), 3.61–3.55 (m, 2H, H-3, H-5), 4.11–4.10 (dd, 2H, H-
6, H-60), 4.52 (d, 1H, J = 9.9 Hz, H-1), 4.85–4.78 (m,
2H, H-2, H-4), 7.06 (d, 2H, J = 8.4 Hz, ortho to the
methyl of STol), 7.33 (d, 2H, J = 8.4 Hz, ortho to the
sulfur of STol). 13C NMR (125 MHz, CDCl3) d: 22.4,
22.6, 22.7, 23.0, 64.0, 67.6, 70.1, 71.8, 78.1, 88.2 (C-1),
131.5, 135.4. ESIMS m/z 460.1 (M+Na+, C19H23N3O7S
requires 460.5).
NMR (500 MHz, CDCl3) ring I d: 3.46–3.50 (m, 3H,
H-2, H-6, H-60), 4.53 (ddd, 1H, J1 = J2 = J3 = 10.0 Hz,
H-5), 5.06 (dd, 1H, J1 = J2 = 10.0 Hz, H-4), 5.44 (dd,
1H, J1 = J2 = 10.0 Hz, H-3), 6.11 (d, 1H, J = 4.0 Hz,
H-1); ring II: d 1.71 (ddd, 1H, J1 = J2 = J3 = 12.5 Hz,
H-2ax), 2.35 (dt, 1H, J1 = 12.5, J2 = 4.5 Hz, H-2eq),
3.30–3.36 (m, 1H, H-4), 3.43–3.48 (m, 1H, H-1), 3.77
(dd, 1H, J1 = J2 = 9.0 Hz, H-5), 3.96 (t, 1H,
J1 = J2 = 9.0 Hz, H-4), 5.00 (dd, 1H, J1 = J2 = 9.5 Hz,
H-6); ring III: d 3.58–3.60 (dd, 1H, J1 = 3.0 Hz,
J2 = 11.5 Hz, H-50), 4.13 (m, 1H, H-4), 4.15 (dd, 1H,
J1 = 3.0 Hz, J2 = 11.5 Hz, H-5), 4.28 (dd, 1H,
J1 = J2 = 5.0 Hz, H-3), 4.76 (dd, 1H, J1 = 1.0 Hz,
J2 = 6.0 Hz, H-2), 5.19 (d, 1H, J = 1.0 Hz, H-1); ring
IV d: 3.16 (dd, 1H, J1 = 1.5, J2 = 2.0 Hz, H-2), 3.17
(m, 1H, H-6), 3.33 (m, 1H, H-60), 3.57 (m, 1H, H-5),
4.46 (d, 1H, J = 1.5 Hz, H-1), 4.59 (m, 1H, H-4), 4.92
To a suspension of 13 (1.2 g, 2.74 mmol) in dry MeOH
(20 mL) and dry dichloromethane (10 mL), catalytic
amount of NaOMe (0.5 M solution in MeOH) was add-
ed at 0 °C. Propagation of the reaction was monitored
by TLC (MeOH 10%, dichloromethane 90%). After
2 h the reaction mixture was neutralized by Dowex H+
and evaporated to dryness. The residue was dissolved
in dry pyridine (20 mL) under argon and added with a
catalytic amount of DMAP. After being stirred at ambi-
ent temperature for 5 min, benzoyl chloride (1.1 mL,
9.45 mmol) was added to the reaction mixture. Propaga-
tion of the reaction was monitored by TLC (EtOAc
30%, hexane 70%), which indicated completion after
4 h. The reaction mixture was diluted with EtOAc and
the organic layer was washed as follows: brine, HCl
(2%), NaHCO3 (satd), and brine. The combined organic
layer was dried over MgSO4, evaporated, and purified
by column chromatography (silica gel, EtOAc/hexane)
to yield 14 as a white solid (1.65 g, 97%). 1H NMR
(300 MHz, CDCl3) d: 2.23 (s, MeSTol), 4.06–3.99 (m,
2H, H-60, H-5), 4.38 (dd, 1H, J1 = 9.9 Hz, J2 = 5.7 Hz,
H-3), 4.63 (dd, 1H, J1 = 12 Hz, J2 = 3 Hz, H-6), 4.85
(br s, 1H, H-3); ring V:
d
4.02 (dd, 1H,
J1 = J2 = 10.0 Hz, H-3), 4.06–4.09 (m, 1H, H-5), 4.57
(m, 2H, H-6, H-60), 4.74 (d, 1H, J = 7.5 Hz, H-1), 5.40
(dd, 1H, J1 = 7.5, J2 = 10.0 Hz, H-2), 5.41 (dd, 1H,
J1 = J2 = 10.0 Hz, H-4). 13C NMR (125 MHz, CDCl3)
d: 20.4, 20.6, 20.6, 20.7, 20.8, 25.9 (C-2), 50.2 (C-6000),
51.0 (C-60), 56.3, 58.2, 58.9, 60.87, 63.6, 64.7, 65.3,
67.5 (C-500), 68.5, 68.7, 69.7, 70.2, 70.7, 71.9, 72.0 (C-
60000), 72.5, 72.9, 74.8, 75.4, 76.7, 77.0, 77.3, 80.0, 83.0,
96.4 (C-10), 98.8 (C-1000), 101.2 (C-10000), 107.8 (C-100),
127.7, 127.8, 128.3, 128.5, 128.7, 129.5, 129.6, 129.9,
130.2, 133.1, 133.6, 134.3, 164.5, 164.9, 165.9, 168.3,
169.6, 170.0, 170.3. ESIMS m/z 1561.6 (M+K+,
C62H67N21O26 requires 1561.4).
4.2.3. Compound 3. Compound 16 (130 mg, 0.085 mmol)
was dissolved in 33% solution of MeNH2 in EtOH
(30 mL) and the mixture was stirred at room tempera-
ture for 24 h. The reagent and the solvent were removed
by evaporation. The residue was dissolved in THF
(4 mL), added with 0.1 M NaOH (2 mL), and stirred
at room temperature for 10 min after which PMe3
(1 M solution in THF, 0.89 mL, 0.89 mmol) was added.
Propagation of the reaction was monitored by TLC
[CH2Cl2/MeOH/H2O/MeNH2 (33% solution in EtOH),
10:15:6:15], which indicated completion after 1.5 h.
The reaction mixture was purified by flash chromatogra-
phy on a short column of silica gel while the column was
washed as follows: THF, EtOAc, MeOH/EtOAc (1:1),
MeOH, and finally the product was eluted with MeNH2
(33% solution in EtOH). The fractions containing the
product were evaporated under vacuum, re-dissolved
in water and evaporated again to afford the free amine
product 3 (53.3 mg, 81%). The product was dissolved
in water, the pH was adjusted to 6.8 by H2SO4
(0.01 M), and lyophilized to afford the sulfate salt of 3
(72.8 mg, containing 73.2% of the product 3 as free
amine form) as a white foamy solid: 1H NMR
(500 MHz, D2O, pH 4.2, adjusted by H2SO4 0.01 M)
ring I d: 3.10–3.17 (m, 1H, H-4), 3.30–3.64 (m, 3H, H-
2, H-6, H-60), 3.75–3.87 (m, 1H, H-3), 3.96 (td, 1H,
J1 = 3.0 Hz, J2 = 8.5 Hz, H-5), 5.81 (d, 1H, J = 5.5 Hz,
H-1); ring II d: 1.60 (ddd, 1H, J1 = J2 = J3 = 13.0 Hz,
H-2ax), 2.20 (dt, 1H, J1 = 13.0 Hz, J2 = 4.0 Hz, H-
2eq), 3.10–3.17 (m, 3H, H-1, H-3, H-4), 3.75–3.87 (m,
1H, H-5), 4.24–4.30 (m, 1H, H-6); ring III d: 3.30–3.64
(d,
1H,
J = 9.9 Hz,
H-1),
5.18
(dd,
1H,
J1 = J2 = 9.9 Hz, H-2), 5.32 (dd, 1H, J1 = J2 = 9.9 Hz,
H-4), 6.87 (d, 2H, J = 7.8 Hz, ortho to the methyl of
STol), 7.33 (d, 2H, J = 8.1 Hz, ortho to the sulfur of
STol), 7.58–7.41 (m, BzO), 8.10–7.99 (m, BzO). 13C
NMR (125 MHz, CDCl3) d: 20.7 (MeSTol), 62.6, 65.8,
69.0, 70.2, 86.0 (C-1), 127.9, 128.0, 128.1, 128.7, 129.2,
129.4, 129.5, 129.7, 132.7, 133.1, 133.3. ESIMS m/z
646.2 (M+Na+, C34H29N3O7S requires 646.7).
˚
4.2.2. Compound 16. To a powdered, flame dried 4 A
molecular sieves (500 mg) anhydrous acetonitrile
(3 mL), was added followed by the addition of acceptor
15 (150 mg, 0.15 mmol) and donor 14 (140 mg,
0.224 mmol). After being stirred for 10 min at room
temperature, the mixture was treated with NIS (50 mg,
0.225 mmol). After additional 5 min at room tempera-
ture, the mixture was cooled to ꢀ40 °C and TfOH
(cat.) was added. Propagation of the reaction was mon-
itored by TLC (EtOAc 50%, hexane 50%). The reaction
was diluted with EtOAc, and filtered through Celite.
After thorough washing of the Celite with EtOAc, the
washes were combined and extracted with 10%
Na2S2O3, saturated (aq) NaHCO3, brine, dried over
MgSO4 and concentrated. The crude was purified by
flash chromatography to yield 16 (130 mg, 57%). 1H