1936 Bull. Chem. Soc. Jpn., 75, No. 9 (2002)
HEADLINE ARTICLES
form and for use as analytical samples.
MHz, CDCl3) δ 2.02 (ddd, 1H, J = 3.6, 4.6 and 14.6 Hz), 2.42
(dd, 1H, J = 5.7 and 14.6 Hz), 3.34 (s, 3H), 3.53 (dd, 1H, J = 3.4
and 10.0 Hz), 3.71 (d, 1H, J = 8.8 Hz), 3.80 (s, 3H), 3.89 (dd, 1H,
J = 10.0 and 11.7 Hz), 4.23–4.27 (m, 3H), 4.29 (d, 1H, J = 11.2
Hz), 4.44 (d, 1H, J = 11.4 Hz), 4.45 (bs, 1H), 4.48 (d, 1H, J =
11.2 Hz), 4.56 (d, 1H, J = 11.4 Hz), 5.20 (dd, 1H, J = 3.6 and 5.7
Hz), 6.87 (d, 2H, J = 8.5 Hz), 7.24 (d, 2H, J = 8.5 Hz), 7.29–7.36
(m, 5H), 7.87 (bs, 1H); 13C NMR (75 MHz, CDCl3) δ 39.2, 55.3,
55.5, 61.9, 63.6, 68.8, 71.2, 73.4, 77.6, 78.9, 92.9, 103.4, 113.8,
128.2, 128.45, 128.54, 129.3, 129.8, 136.7, 159.3, 161.5; EI-MS
m/z 563 (M + 2, 0.6%), 561 (M+, 0.9), 527 (4.2), 525 (5.4), 391
(100), 389 (93.8); EI-HRMS Calcd for C25H3035Cl3NO7 (M+):
561.1087, Found: m/z 561.1083.
16S: Rf = 0.44 (1:3 EtOAc–hexane); [α]D24.0 +11.2 (c 1.16,
CHCl3); IR (neat) 1045, 1105, 1250, 1515, 1720, 2835, 2930,
3330 cm−1; 1H NMR (300 MHz, CDCl3) δ 1.96 (ddd, 1H, J = 3.6,
5.2 and 14.6 Hz), 2.39 (dd, 1H, J = 5.9 and 14.4 Hz), 3.35 (s, 3H),
3.78 (s, 3H), 3.85 (d, 1H, J = 8.8 Hz), 4.14 (bdd, 1H, J = 3.6 and
5.2 Hz), 4.22–4.52 (m, 6H), 5.23 (dd, 1H, J = 3.6 and 5.9 Hz),
5.26 (bd, 1H, J = 11.0 Hz), 5.35 (bd, 1H, J = 17.6 Hz), 6.05 (dd,
1H, J = 11.0 and 17.6 Hz), 6.94 (d, 2H, J = 8.8 Hz), 7.21–7.31
(m, 7H), 8.30 (bs, 1H) ; 13C NMR (75 MHz, CDCl3) δ 39.2, 55.2,
55.4, 62.6, 70.6, 71.6, 73.2, 78.0, 79.9, 93.1, 103.7, 113.7, 115.9,
128.3, 128.5, 128.9, 129.1, 130.4, 134.4, 136.6, 159.1, 160.7; EI-
MS m/z 559 (M + 2, 0.2%), 557 (M+, 0.2), 528 (0.3), 526 (0.3),
468 (0.3), 466 (0.3), 388 (4.6), 387 (20.7), 386 (6.8), 385 (30.2),
121 (100); EI-HRMS Calcd for C26H3035Cl3NO6 (M+): 557.1138,
Found: m/z 557.1141. Found: C, 56.23; H, 5.28; N, 2.42%. Calcd
for C26H30Cl3NO6: C, 55.88; H, 5.41; N, 2.51%.
17R: Rf = 0.32 (1:2 EtOAc–hexane); [α]D19.0 −23.4 (c 0.60,
CHCl3); IR (neat) 1045, 1105, 1250, 1515, 1715, 2870, 2930,
2950, 3300, 3400 cm−1; 1H NMR (300 MHz, CDCl3) δ 1.95 (ddd,
1H, J = 3.5, 5.4 and 14.6 Hz), 2.32 (dd, 1H, J = 5.9 and 14.6 Hz),
3.35 (s, 3H), 3.59 (d, 1H, J = 9.3 Hz), 3.92 (d, 1H, J = 9.3 Hz),
3.79 (s, 3H), 3.93 (d, 1H, J = 9.3 Hz), 4.08 (d, 1H, J = 10.7 Hz),
4.10 (d, 1H, J = 2.7 Hz), 4.22–4.25 (m, 1H), 4.27 (d, 1H, J = 9.3
Hz), 4.30 (d, 1H, J = 11.2 Hz), 4.36 (d, 1H, J = 10.7 Hz), 4.51 (d,
1H, J = 11.2 Hz), 5.19 (dd, 1H, J = 2.9 and 5.7 Hz), 6.89 (d, 2H,
J = 8.7 Hz), 7.13–7.33 (m, 7H), 8.55 (bs, 1H); 13C NMR (75
MHz, CDCl3) δ 39.0, 55.3, 55.5, 63.3, 64.5, 68.6, 71.5, 73.4, 80.0,
80.2, 93.0, 103.7, 113.8, 128.4, 128.55, 128.64, 128.9, 129.7,
136.3, 159.4, 162.5; EI-MS m/z 563 (M + 2, 1.1%), 561 (M+,
1.4), 527 (6.4), 525 (8.8), 412 (2.2), 391 (100), 389 (100); EI-
HRMS Calcd for C25H3035Cl3NO7 (M+): 561.1087, Found: m/z
561.1088.
(S)-4-[(2R,3R,5S)-3-Benzyloxy-5-methoxyoxolan-2-yl]-4-(4-
methoxybenzyloxymethyl)-1,3-oxazolidin-2-one (18S) and Its
(R)-Isomer (18R). To a solution of the mixture (ca. 8:1) of
amides 17S and 17R (186 mg, 0.330 mmol) in CH2Cl2 (4 mL) was
added DBU (0.010 mL, 0.0660 mmol) and the mixture was stirred
at 25 °C for 2 h. Removal of the solvent gave a residue, which
was purified by column chromatography (8 g silica gel, 1:2
EtOAc–hexane as an eluent) to afford S-isomer 18S (16.4 mg,
11%) as a pale yellow syrup: Rf = 0.39 (2:1 EtOAc–hexane);
[α]D26.0 +37.4 (c 0.87, CHCl3); IR (neat) 1050, 1110, 1180, 1250,
1360, 1515, 1615, 1745, 1770, 1780, 2910, 3000, 3320, 3440
cm−1; 1H NMR (300 MHz, CDCl3) δ 2.04 (ddd, 1H, J = 2.9, 4.9
and 13.7 Hz), 2.27 (ddd, 1H, J = 1.6, 5.7 and 13.7 Hz), 3.34 (s,
3H), 3.41 (d, 1H, J = 9.0 Hz), 3.47 (d, 1H, J = 9.0 Hz), 3.79 (s,
3H), 4.04 (d, 1H, J = 11.0 Hz), 4.04–4.09 (m, 2H), 4.25 (d, 1H, J
= 11.6 Hz), 4.31 (d, 1H, J = 8.5 Hz), 4.390 (d, 1H, J = 11.0 Hz),
4.392 (d, 1H, J = 11.6 Hz), 4.44 (d, 1H, J = 8.5 Hz), 5.18 (dd,
1H, J = 2.9 and 5.7 Hz), 5.56 (s, 1H), 6.89 (d, 2H, J = 8.8 Hz),
7.16–7.39 (m, 7H); 13C NMR (75 MHz, CDCl3) δ 39.4, 55.2, 55.4,
60.6, 71.2, 72.0, 72.3, 73.1, 78.3, 78.9, 103.7, 113.9, 128.32,
128.34, 128.7, 129.2, 129.7, 136.4, 159.2, 159.5; EI-MS m/z 443
(M+, 6.1%), 411 (0.9), 352 (2.0), 322 (2.0), 261 (3.9), 260 (23.2),
236 (8.7), 235 (51.6), 234 (20.4), 121 (100); EI-HRMS Calcd for
C24H29NO7 (M+): 443.1944, Found: m/z 443.1944.
16R: Rf = 0.44 (1:3 EtOAc–hexane); [α]D22.0 −2.9 (c 1.62,
CHCl3); IR (neat) 1050, 1110, 1250, 1515, 1715, 2870, 2930,
3330, 3400 cm−1; 1H NMR (300 MHz, CDCl3) δ 1.87 (ddd, 1H, J
= 3.4, 5.1 and 14.4 Hz), 2.28 (bdd, 1H, J = 5.8 and 14.4 Hz), 3.27
(s, 3H), 3.71 (s, 3H), 3.74 (d, 1H, J = 8.8 Hz), 3.96 (d, 1H, J =
11.0 Hz), 3.99 (d, 1H, J = 8.8 Hz), 4.04 (d, 1H, J = 3.4 Hz), 4.13
(bdd, 1H, J = 3.4 and 5.1 Hz), 4.19 (d, 1H, J = 11.4 Hz), 4.28 (d,
1H, J = 11.0 Hz), 4.36 (d, 1H, J = 11.4 Hz), 5.13 (dd, 1H, J =
3.4 and 5.8 Hz), 5.20 (d, 1H, J = 11.0 Hz), 5.27 (d, 1H, J = 17.6
Hz), 6.11 (dd, 1H, J = 11.0 and 17.6 Hz), 6.80 (d, 2H, J = 8.8
Hz), 7.05–7.24 (m, 7H), 8.15 (bs, 1H); 13C NMR (75 MHz,
CDCl3) δ 39.1, 55.2, 55.5, 61.1, 70.1, 71.1, 73.2, 79.4, 80.5, 93.0,
103.2, 113.8, 115.2, 128.1, 128.4, 128.6, 129.7, 129.8, 136.4,
136.8, 159.3, 160.5; EI-MS m/z 559 (M + 2, 0.1%), 557 (M+,
0.1), 528 (0.1), 526 (0.1), 388 (0.4), 387 (1.6), 386 (0.7), 385
(2.4), 121 (100); EI-HRMS Calcd for C26H3035Cl3NO6 (M+):
557.1138, Found: m/z 557.1138. Found: C, 56.22; H, 5.27; N,
2.44%. Calcd for C26H30Cl3NO6: C, 55.88; H, 5.41; N, 2.51%.
Overman rearrangement of Z-allylic imidate 6Z derived from
allylic alcohol 15Z was carried out by the same procedure to af-
ford 16S and 16R in 1:5 ratio (70% yield).
A Mixture of N-{(S)-1-Hydroxy-3-(4-methoxybenzyloxy)-2-
[(2R,3R,5S)-3-benzyloxy-5-methoxyoxolan-2-yl]propan-2-
yl}trichloroacetamide (17S) and Its (R)-Isomer (17R). Ozone
was introduced into a solution of a mixture (ca. 7:1) of the rear-
ranged products 16S and 16R (289 mg, 0.516 mmol) in MeOH
(5.6 mL) at −78 °C for 9 min. After the complete consumption of
the starting material had been confirmed (TLC analysis), excess
ozone was purged by a stream of argon gas. To this solution was
added portionwise NaBH4 (78.1 mg, 2.07 mmol) at −78 °C. The
resulting mixture was stirred at 0 °C for 15min, then quenched by
addition of 1 M aqueous HCl solution. The products were extract-
ed with EtOAc and the combined organic layer was washed suc-
cessively with saturated NaHCO3 solution and brine, and then
dried. Removal of the solvent gave a residue, which was purified
by column chromatography (15 g silica gel, 1:4 EtOAc–hexane as
an eluent) to afford a mixture (ca. 8:1) of amides 17S and 17R
(206 mg, 71%) as a colorless syrup.
Further elution gave R-isomer 18R (130 mg, 89%) as a pale
yellow syrup: Rf = 0.27 (2:1 EtOAc–hexane); [α]D25.5 +24.4 (c
0.67, CHCl3); IR (neat) 1045, 1110, 1250, 1515, 1745, 1755,
2865, 2920, 3290 cm−1; 1H NMR (300 MHz, CDCl3) δ 2.05 (ddd,
1H, J = 2.8, 5.9 and 14.4 Hz), 2.27 (ddd, 1H, J = 2.0, 5.6 and
14.4 Hz), 3.34 (s, 3H), 3.44 (d, 1H, J = 9.0 Hz), 3.48 (d, 1H, J =
9.0 Hz), 3.80 (s, 3H), 3.86 (d, 1H, J = 9.4 Hz), 3.94–3.98 (m, 1H),
3.98 (d, 1H, J = 11.5 Hz), 4.21 (d, 1H, J = 4.4 Hz), 4.26 (d, 1H, J
A small amount of the mixture was separated by PLC (1:9
EtOAc–hexane as an eluent) to give each diastereomer in pure
form and for use as analytical samples.
17S: Rf = 0.36 (1:2 EtOAc–hexane); [α]D22.0 +25.0 (c 0.71,
CHCl3); IR (neat) 1040, 1110, 1175, 1250, 1455, 1505, 1520,
1615, 1715, 2840, 2935, 3005, 3380, 3460 cm−1; H NMR (300
1