Lewis Acid-Promoted Cycloaddition Reactions
J . Org. Chem., Vol. 63, No. 17, 1998 5927
7.18-7.22 (m, 3 H), 7.47-7.52 (m, 2 H); 13C NMR (50.1 MHz,
CDCl3) δ (ppm) -1.909, -1.646, 16.40, 16.52, 17.22, 23.78,
26.00 (d, J CP ) 188 Hz), 28.57, 32.89, 62.66 (d, J CP ) 7.3 Hz),
63.87, 126.9, 128.7, 130.8, 133.4, 168.6 (d, J CP ) 7.3 Hz); IR
(neat) 2956, 2904, 1715, 1578, 1251 cm-1; MS (EI) m/z 564;
exact mass M+ 564.1430 (calcd for C23H41O5PSeSi2 564.1395).
Eth yl r -1-(Diisop r op oxyp h osp h or yl)-c-2-[(p h en ylsele-
n o)(t r im et h ylsilyl)m et h yl]-1-cyclop r op a n eca r b oxyla t e
(3e) (Rf 0.6 (CH2Cl2: ether ) 2:1)): colorless oil; 1H NMR (200
MHz, CDCl3) δ (ppm) 0.053 (s, 9 H), 1.18 (t, J ) 7.1 Hz, 3 H),
1.28-1.41 (m, 12 H), 1.58 (ddd, J ) 9.8, 7.4, 4.3 Hz, 1 H), 1.85
(ddd, J ) 13.6, 9.0, 4.3 Hz, 1 H), 2.05-2.26 (m, 1 H), 2.58 (d,
J ) 12.5 Hz, 1 H), 3.78 (dd, J ) 10.8, 7.1 Hz, 1 H), 3.97 (dd,
J ) 10.8, 7.2 Hz, 1 H), 4.66-4.88 (m, 2 H), 7.19-7.22 (m, 3
H), 7.50-7.55 (m, 2 H); 13C NMR (50.1 MHz, CDCl3) δ (ppm)
-1.880, 13.95, 23.99, 24.05, 24.13, 26.81 (d, J CP ) 189 Hz),
mmol) in three portions at -78 °C. The mixture was stirred
for 2 h at -78 °C. Saturated aqueous Na2SO4 solution (2 mL)
was added to the reaction mixture. The mixture was extracted
with ether (60 mL × 5). The organic phase was dried (MgSO4)
and evaporated in vacuo to give 8 (622 mg, 94%) (Rf 0.4 (ether:
methanol ) 19:1)). 8: pale yellow oil; 1H NMR (400 MHz,
CDCl3) δ (ppm) 1.31 (t, J ) 7.1 Hz, 3 H), 1.32-1.37 (m, 6 H),
1.47 (ddd, J ) 10.4, 7.1, 4.8 Hz, 1 H), 1.60 (ddd, J ) 14.3, 8.9,
4.8 Hz, 1 H), 1.73 (brs, 1 H), 2.13 (m, 1 H), 3.48 (dd, J ) 12.0,
9.0 Hz, 1 H), 3.96 (dd, J ) 12.0 Hz, 5.0 Hz, 1 H), 4.13-4.23
(m, 4 H), 4.25 (q, J ) 7.1 Hz, 2 H); 13C NMR (100.6 MHz,
CDCl3) δ (ppm) 14.11, 16.23 (d, J CP ) 3.1 Hz), 16.36, 16.42,
25.01 (d, J CP ) 188 Hz), 28.09 (d, J CP ) 3.1 Hz), 60.99, 61.94,
62.79 (d, J CP ) 6.1 Hz), 62.92 (d, J CP ) 6.1 Hz), 168.6 (d, J CP
) 6.9 Hz); IR (neat) 3400, 2986, 2918, 1725, 1232 cm-1; MS
(EI) m/z 280; exact mass M+ 280.1107 (calcd for C11H21O6P
280.1076).
28.60, 32.46, 61.42, 70.97 (d, J CP ) 5.9 Hz), 71.07 (d, J CP
)
4.4 Hz), 126.9, 128.7, 130.7, 133.7, 168.8 (d, J CP ) 5.9 Hz); IR
(neat) 2980, 1715, 1578, 1251 cm-1; MS (EI) m/z 520; exact
mass M+ 520.1306 (calcd for C22H37O5PSeSi 520.1314).
(l)-Men th yl r -1-(Dim eth oxyp h osp h or yl)-c-2-[(p h en yl-
selen o)(tr im eth ylsilyl)m eth yl]-1-cyclopr opan ecar boxylate
(3f) (Rf 0.75 (CH2Cl2:ether ) 2:1)): colorless crystals; mp 74-
Diet h yl 3-Oxa b icyclo[3.1.0]h exa n -2-on e-1-p h osp h on -
a te (9). To a solution of 8 (756 mg, 2.7 mmol) in EtOH (2.5
mL) was added dropwise a 50% (wt %) aqueous NaOH solution
(237 µL) at 0 °C. The resulting solution was stirred for 2 h at
55 °C and then for 0.5 h at 18 °C. The EtOH was evaporated,
and the remaining solution was diluted with water (1 mL).
The aqueous phase was acidified with KHSO4 and extracted
with Et2O twice. The combined organic extracts were dried
(MgSO4) and evaporated to give 9 (577 mg, 91%) (Rf 0.2 (ether:
methanol ) 19:1)). 9: pale yellow oil; 1H NMR (400 MHz,
CDCl3) δ (ppm) 1.31 (ddd, J ) 10.4, 4.9, 4.9 H, 1 H), 1.37 (t, J
) 7.4 Hz, 3 H), 1.39 (t, J ) 7.4 Hz, 3 H), 1.88 (ddd, J ) 15.3,
7.8, 4.9 Hz, 1 H), 2.77 (dddd, J ) 10.1, 7.8, 4.9, 4.9 Hz, 1 H),
4.20-4.31 (m, 5 H), 4.40 (dd, J ) 9.5, 4.9 Hz, 1 H); 13C NMR
(100.6 MHz, CDCl3) δ (ppm) 16.22, 16.28, 17.63 (d, J CP ) 3.1
Hz), 22.57 (d, J CP ) 209 Hz), 24.66 (d, J CP ) 1.5 Hz), 63.64 (d,
J CP ) 6.9 Hz), 63.66 (d, J CP ) 6.1 Hz), 67.73 (d, J CP ) 3.1 Hz),
1
76 °C (hexane); H NMR (400 MHz, CDCl3) δ (ppm) -0.038
(s, 9 H, H13), 0.482 (d, J ) 7.0 Hz, 3 H, H14), 0.822 (d, J ) 7.1
Hz, 3 H), 0.910 (d, J ) 6.6 Hz, 3 H), 0.776-1.07 (m, 3 H), 1.39-
1.51 (m, 2 H), 1.61-1.68 (m, 3 H, including H3b), 1.90 (ddd, J
) 14.3, 8.9, 4.3 Hz, H3a), 2.08-2.23 (m, 3 H, including H2),
2.65 (d, J ) 12.8 Hz, 1 H, H6), 3.81 (d, J ) 10.8 Hz, 3 H, H7),
3.85 (d, J ) 10.8 Hz, 3 H, H8), 4.68 (ddd, J ) 10.8, 10.8, 4.5
Hz, 1 H, H5), 7.18-7.21 (m, 3 H, H11,12), 7.51-7.54 (m, 2 H,
H
10); selected observed NOEs in the 2D-NOESY spectrum were
H2-H3a, H2-H6, H2-H13, H3a-H3b, H3b-H6, H3b-H13, H6-H10
H6-H13, and H10-H14
13C NMR (100.6 MHz, CDCl3) δ (ppm)
-1.673 (CH3, J CH ) 119 Hz, C13), 16.17 (CH3, J CH ) 124 Hz,
14), 21.11, 22.10, 23.07, 24.12 (J cp ) 3.1 Hz, C3), 25.58, 25.83
(d, J CP ) 190 Hz, C1), 27.40 (C6), 31.46 (CH, J CP ) 2.3 Hz, J CH
) 161 Hz, C2), 31.50 (CH, J CH ) 123 Hz), 34.29 (CH2, J CH
,
;
171.5 (d, J CP ) 11 Hz); IR (neat) 2988, 2918, 1773, 1255 cm-1
;
C
MS (EI) m/z 234; exact mass M+ 234.0673 (calcd for C9H15O5P
234.0658).
)
c-2-(Acetoxym eth yl)-r -1-(d ieth oxyp h osp h or yl)-1-cyclo-
p r op a n eca r boa m id e (10). The lactone 9 (640 mg, 2.73
mmol) was dissolved in methanol (10 mL), and methanol
saturated with ammonia (ca. 5.8 M, 5.0 mL, 29 mmol) were
added and the solution stirred for 17 h at room temperature.
The solvent was the evaporated in vacuo and the residue
dissolved in dry CH2Cl2 (10 mL) and cooled to 0 °C, and
triethylamine (326 mg, 3.27 mmol) and (dimethylamino)-
pyridine (20 mg) were added to the solution, followed by
dropwise addition of acetic anhydride (334 mg, 3.27 mmol).
After stirring for 4 h at 0 °C, water was added and the solution
was extracted with CH2Cl2. The organic layers were dried
(Na2SO4) and evaporated. The residue was purified by column
chromatography over silica gel eluting with ether-methanol
(19:1) to give 10 (698 mg, 87%) (Rf 0.3 (ether:methanol ) 19:
1)). 10: colorless oil; 1H NMR (400 MHz, CDCl3) δ (ppm) 1.32-
1.39 (m, 6 H), 1.43 (ddd, J ) 14.1, 9.2, 4.8 Hz, 1 H), 1.73 (ddd,
J ) 10.1, 7.0, 4.8 Hz, 1 H), 2.05 (s, 3 H), 2.03-2.14 (m, 1 H),
3.96 (dd, J ) 11.8, 8.9 Hz, 1 H), 4.11-4.24 (m, 4 H), 4.37 (ddd,
126 Hz), 40.68 (CH2, J CH ) 125 Hz), 47.22 (CH, J CH ) 125
Hz), 53.34 (CH, J CP ) 8.4 Hz, J CH ) 148 Hz, C8), 53.42 (CH,
J CP ) 6.9 Hz, J CH ) 148 Hz, C7), 76.05 (CH, C6), 127.2 (CH,
J CH ) 161, 7.3 Hz, C12), 128.9 (CH, J CH ) 160 Hz, C11), 130.1
(C, C9), 134.1 (CH, J CH ) 164 Hz, C10), 168.1 (C, J CP ) 6.9 Hz,
C4); nondecoupling spectrum was measured at 50.1 MHz and
carbon multiplicity was only partially assigned because of
complexity; partial 1H and 13C assignments were also deter-
mined by COSY, NOESY, HMQC, and TOCSY spectra; IR
(KBr) 2960, 2872, 1705, 1578, 1257 cm-1; MS (EI) m/z 574;
exact mass M+ 574.1808 (calcd for C26H43O5PSeSi 574.1783).
Anal. Calcd for C26H43O5PSeSi: C, 54.44; H, 7.56. Found: C,
22.5
54.42; H, 7.51; [R]D
-42.3° (c ) 1.0, CHCl3).
Eth yl r -1-(Dieth oxyp h osp h or yl)-c-2-for m yl-1-cyclop r o-
p a n eca r boxyla te (7). To a solution of 3b (491 mg, 1.0 mmol)
in THF (20 mL) and water (10 mL) was added NaIO4 (1.07 g,
5.0 mmol) with vigorous stirring. The mixture was stirred for
4.5 h at room temperature (22 °C). The reaction mixture was
concentrated in vacuo and poured into ether (100 mL) and
saturated aqueous NaHCO3 solution (50 mL). The organic
layer was separated. The water layer was extracted with
additional ether (100 mL × 5). The combined organic layer
was washed with water, dried (MgSO4), and concentrated in
vacuo to give 7 (270 mg, 97%) (Rf 0.4 (ether:methanol ) 19:
1)). 7: pale yellow oil; 1H NMR (200 MHz, CDCl3) δ (ppm)
1.30 (t, J ) 7.2 Hz, 3 H), 1.35 (t, J ) 7.1 Hz, 6 H), 1.91 (ddd,
J ) 14.7, 8.7, 5.0 Hz, 1 H), 2.15 (ddd, J ) 12.0, 6.6, 5.0 Hz, 1
H), 2.57 (dddd, J ) 12.2, 8.7, 6.6, 5.1 Hz, 1 H), 4.11-4.30 (m,
6 H), 9.29 (d, J ) 5.1 Hz, 1 H); 13C NMR (50.1 MHz, CDCl3) δ
(ppm) 13.83, 16.11, 16.22, 16.89, 29.26 (d, J CP ) 183 Hz), 32.43
(d, J CP ) 2.9 Hz), 62.24, 63.11 (d, J CP ) 5.9 Hz), 63.23 (d, J CP
) 5.9 Hz), 166.2 (d, J CP ) 4.4 Hz), 196.6; IR (neat) 2988, 1729,
1257 cm-1; MS (EI) m/z (relative intensity) 279 (5.4, M + 1),
263 (5.4), 233 (25), 205 (100); MS (FAB) m/z 279 (MH+).
Eth yl r -1-(Dieth oxyp h osp h or yl)-c-2-h yd r oxym eth yl-1-
cyclop r op a n e ca r boxyla te (8). To a solution of 7 (653 mg,
J ) 11.8, 6.0, 1.2 Hz, 1 H), 5.68 (brs, 1 H), 7.37 (brs, 1 H); 13
NMR (100.6 MHz, CDCl3) δ (ppm) 14.40 (J CP ) 3.1, J CH ) 166
Hz, CH2), 16.31 (J CP ) 6.1, J CH ) 127 Hz, CH3), 16.36 (J CP
C
)
5.3, J CH ) 127 Hz, CH3), 20.76 (J CH ) 129 Hz, CH3), 24.19
(J CP ) 2.3, J CH ) 167 Hz, CH), 24.90 (J CP ) 181 Hz, C), 62.25
(J CP ) 1.5, J CH ) 150 Hz, CH2), 63.06 (J CP ) 6.1, J CH ) 148
Hz, CH2), 63.23 (J CP ) 6.9, J CH ) 149 Hz, CH2), 167.2 (J CP
)
9.2 Hz, C), 170.7 (C); IR (neat) 3468, 3202, 2988, 1742, 1676,
1615, 1241 cm-1; MS (EI) m/z 293; exact mass M+ 293.1046
(calcd for C11H20O6NP 293.1029).
Dieth yl t-2-(Acetoxym eth yl)-r -1-[N-(ter t-bu toxycar bon -
yl)a m in o]-1-cyclop r op a n ep h osp h on a te (11). A solution of
10 (110 mg, 0.375 mmol) and t-BuOH (1.9 mL) was heated to
70 °C. Lead tetraacetate (665 mg, 1.50 mmol) was added and
the mixture was heated at reflux for 5 h. After cooling to room
temperature, ether (0.9 mL) followed by NaHCO3 (60 mg) were
added, and the mixture was stirred for 10 min. The mixture
was filtered through a short plug of silica gel and the filtrate
evaporated. The residue was purified by column chromatog-
i
2.35 mmol) in PrOH (13.4 mL) was added NaBH4 (36 mg, 0.94