5170
J. M. Harris, G. A. O'Doherty / Tetrahedron 57 )2001) 5161±5171
CDCl3) d 161.0, 141.5, 135.1, 128.5, 128.4, 126.8, 121.7,
80.8, 79.6, 73.8, 67.3; FABHRMS Calcd for
[C13H12O41Na]1: 255.0633. Found: 255.0634.
J9.6, 5.7 Hz, 1H), 6.22 ?d, J9.9 Hz, 1H), 5.37 ?d,
J3.0 Hz, 1H), 5.10 ?dd, J4.5, 1.2 Hz, 1H), 4.86 ?dd,
J5.4, 4.5 Hz, 1H), 4.52?bs, 1H); 13C NMR ?75 MHz,
CDCl3) d 160.9, 140.5, 134.7, 128.9, 128.7, 126.6, 123.1,
84.3, 83.5, 77.9, 68.2; CIHRMS Calcd for
[C13H12O41NH4]1: 250.1079. Found: 250.1094.
1.1.26. 3-epi-3-Benzoyl-altholactone $21) and 3-benzoyl
isoaltholactone $22). 3-epi-Altholactone )1a) and isoaltho-
lactone )1b) as a 1:1 mixture, 6.0 mg ?0.026 mmol) was
dissolved in 0.3 mL of CH2Cl2,9.5 mg ?0.078 mmol) of
DMAP, and 9 mL ?0.08 mmol) of benzoyl chloride were
added and stirred for 6 h. The reaction was quenched with
10 mL of Et2O and 10 mL of sat aq NaHCO3. The phases
were separated and the aq layer was extracted ?5£10 mL)
with Et2O. The organic fractions were combined, dried
?MgSO4), concentrated, and the crude product was puri®ed
by silica gel chromatography eluting with ?30% EtOAc/
hexanes) to give 3.5 mg ?0.010 mmol, 38%) of 3-epi-3-
benzoylaltholactone )21) and 3.5 mg ?0.01 mmol, 38%) of
3-benzoylisoaltholactone )22). 3-epi-3-Benzoylaltholactone
1.1.28. 3-epi-3-Tri¯uoromethanesulfonyl-altholactone $24)
and 3-tri¯uoromethanesulfonyl-isoaltholactone $25). 3-
epi-Altholactone )1a) and isoaltholactone )1b) as a 1:1
mixture, 4.0 mg ?0.017 mmol) was dissolved in 0.2 mL of
CH2Cl2, 20 mL ?0.25 mmol) of pyridine, and 32 mL
?0.19 mmol) of tri¯uoromethanesulfonic anhydride were
added and stirred for 0.5 h. The reaction was quenched
with 10 mL of Et2O and 10 mL of sat aq NaHCO3. The
phases were separated and the aq layer was extracted
?5£10 mL) with Et2O. The organic fractions were
combined, dried ?MgSO4), concentrated, and the crude
product was puri®ed by silica gel chromatography eluting
with ?30% EtOAc/hexanes) to give 2.5 mg ?0.007 mmol,
40%) of compound ?24) and 2.5 mg ?0.007 mmol, 40%) of
compound ?25). 3-epi-3-Tri¯uoromethanesulfonyl-altholac-
)21): Rf ?30% EtOAc/hexanes)0.15; [a]21 126.3?c
D
1
0.34, CH2Cl2); H NMR ?500 MHz, CDCl3) d 8.12±8.10
?m, 1H), 7.50±7.46 ?m, 2H), 7.34±7.19 ?m, 5H), 6.98 ?dd,
J10.0, 3.0 Hz, 1H), 6.20 ?dd, J10.0, 1.0 Hz, 1H), 5.99
?dd, J5.5, 4.0 Hz, 1H), 5.55 ?dd, J8.0, 5.0 Hz, 1H), 5.27
?d, J4.5 Hz, 1H), 4.97 ?ddd, J8.0, 3.5, 1.5 Hz, 1H); 13C
NMR ?75 MHz, CDCl3) d 164.6, 160.2, 142.0, 134.6, 133.3,
129.4, 128.7, 128.4, 128.3, 128.1, 126.9, 121.2, 80.1, 78.1,
73.8, 67.4; FABHRMS Calcd for [C20H16O51H]1:
337.1076. Found: 337.1085. 3-benzoylisoaltholactone
tone )24): Rf ?30% EtOAc/hexanes)0.25; [a]21 111.1
D
?c 0.35, CH2Cl2); 1H NMR ?500 MHz, CDCl3) d 7.43±7.35
?m, 5H), 6.88 ?dd, J10.5, 3.0 Hz, 1H), 6.17 ?dd, J10.5,
2.0 Hz, 1H), 5.56 ?dd, J9.5, 5.0 Hz, 1H), 5.40 ?dd, J5.0,
3.0 Hz, 1H), 5.18 ?d, J3.0 Hz, 1H), 4.96 ?ddd, J9.0,
3.0, 1.5 Hz, 1H); 13C NMR ?75 MHz, CDCl3) d 158.6,
141.3, 132.1, 130.9, 129.4, 128.6, 127.2, 125.5, 120.8,
119.2, 116.7, 86.4, 79.4, 68.2, 66.6; FABHRMS Calcd
for [C14H11O6SF31Na]1: 387.0126. Found: 387.0103.
)22): Rf ?30% EtOAc/hexanes)0.28; [a]21 236.5 ?c
D
1
0.15, CH2Cl2); H NMR ?500 MHz, CDCl3) d 8.01±7.99
?m, 1H), 7.61±7.58 ?m, 1H), 7.50±7.33 ?m, 8H), 6.91 ?dd,
J10.0, 3.5 Hz, 1H), 6.27 ?dd, J10.0, 1.0 Hz, 1H), 5.44
?dd, J5.5, 5.5 Hz, 1H), 5.41 ?dd, J5.5, 5.5 Hz, 1H), 5.24
?d, J5.0 Hz, 1H), 5.10 ?ddd, J5.5, 4.0, 1.0 Hz, 1H); 13C
NMR ?75 MHz, CDCl3) d 165.7, 160.7, 142.0, 137.7, 133.7,
129.8, 128.8 ?2C), 128.6 ?2C), 125.6, 122.4, 81.6, 78.4,
76.2, 68.2; FABHRMS Calcd for [C20H16O51H]1:
337.1076. Found: 337.1084.
3-Tri¯uoromethanesulfonyl-isoaltholactone )25): Rf ?30%
1
EtOAc/hexanes)0.45; [a]21 29.0 ?c 0.20, CH2Cl2); H
D
NMR ?500 MHz, CDCl3) d 7.45±7.38 ?m, 5H), 6.85 ?dd,
J10.5, 3.0 Hz, 1H), 6.22 ?dd, J10.0, 1.0 Hz, 1H),
5.28?dd, J7.0, 5.5 Hz, 1H), 5.26 ?d, J4.5 Hz, 1H), 5.20
?d, J5.5, 5.5 Hz, 1H), 5.09 ?ddd, J7.5, 3.5, 1.0 Hz, 1H);
13C NMR ?75 MHz, CDCl3) d 159.0, 141.3, 135.5, 130.9,
129.4, 129.2, 128.8, 125.4, 122.4, 119.6, 110.0, 88.1, 81.5,
75.2, 67.8; FABHRMS Calcd for [C14H11O6SF31Na]1:
387.1026. Found: 387.0150.
1.1.27. Altholactone $1b) and 2-epi-altholactone $1d).
Compound 2a ?6.0 mg, 0.026 mmol) was dissolved in
0.3 mL of CH2Cl2 and a catalytic amount of CSA was
added to the solution at rt. The reaction was stirred for
12 h at rt. The reaction was quenched with 10 mL of Et2O
and 10 mL of sat aq NaHCO3. The phases were separated
and the aq layer was extracted ?5£10 mL) with Et2O. The
organic fractions were combined, dried ?MgSO4), concen-
trated, and the crude product was puri®ed by silica gel chro-
matography eluting with ?100% Et2O) to give 1b and 1d as a
1:1 mixture, 5.0 mg ?0.022 mmol, 80%). Altholactone )1b):
1.1.29. 3-Forymloxy-altholactone $not shown). Com-
pound 24 ?7.0 mg, 0.019 mmol) was dissolved in 0.2 mL
of DMF and cesium formate ?10 mg, 0.58 mmol) was
added to the solution at rt. The reaction was stirred for 4 h
at rt. The reaction was quenched with 10 mL of Et2O and
10 mL of sat aq NaHCO3. The phases were separated and
the aq layer was extracted ?5£10 mL) with Et2O. The
organic fractions were combined, dried ?MgSO4), concen-
trated, and the crude product was puri®ed by silica gel chro-
matography eluting with ?100% Et2O) to give 3-forymloxy-
altholactone ?3 mg, 0.012 mmol) in a 60% yield: Rf ?100%
R ?100% Et2O)0.29; [a]21 1162.8 ?c 0.09, EtOH); IR
D
f
?thin ®lm, cm21) 3430, 2939, 2921, 2854, 1727, 1639, 1452,
1389, 1260, 1197, 1091, 1056; 1H NMR ?300 MHz, CDCl3)
d 7.39±7.30 ?m, 5H), 7.00 ?dd, J9.9, 4.8 Hz, 1H), 6.24 ?d,
J9.9 Hz, 1H), 4.95 ?dd, J5.4, 2.4 Hz, 1H), 4.75 ?d,
J5.7 Hz, 1H), 4.66 ?dd, J5.4 Hz, 1H), 4.46?dd, J5.7,
2.4 Hz, 1H); 13C NMR ?75 MHz, CDCl3) d 160.9, 140.2,
138.0, 128.7, 128.4, 126.1, 123.7, 86.2, 86.0, 83.8, 68.2;
CIHRMS Calcd for [C13H12O41NH4]1: 250.1079. Found:
250.1090. 2-epi-Altholactone )1d). Rf ?100% Et2O)0.42;
Et2O)0.26; [a]21 150.4 ?c 0.14, CH2Cl2); IR ?thin ®lm,
D
cm21) 2958, 2926, 2854, 1732, 1716, 1651, 1463, 1455,
1246, 1150, 1101, 1069, 1025; 1H NMR ?500 MHz,
CDCl3) d 8.13 ?s, 1H), 7.36±7.31 ?m, 5H), 7.05 ?dd,
J10.0, 5.5 Hz, 1H), 6.30 ?d, J10.0 Hz, 1H), 5.50 ?d,
J3.5 Hz, 1H), 5.00 ?d, J4.0 Hz, 1H), 4.99 ?dd, J4.0,
1.0 Hz, 1H), 4.64 ?dd, J5.5, 4.5 Hz, 1H); 13C NMR
?75 MHz, CDCl3) d 164.9, 159.0, 139.0, 130.9, 128.7
?2C), 126.2, 124.8, 85.9, 83.8, 83.2, 69.1; CIHRMS Calcd
for [C14H12O51NH4]1: 278.1028. Found: 278.1037.
[a]21 1214.5 ?c 0.11, EtOH); IR ?thin ®lm, cm21) 3430,
D
1
2956, 2925, 2857, 1731, 1450, 1390, 1248, 1095, 1044; H
NMR ?300 MHz, CDCl3) d 7.45±7.33 ?m, 5H), 7.01 ?dd,