PAPER
Synthesis of Allylic Spiro Ethers and Lactones
3623
1H (400 MHz) and 13C (100.4 MHz) NMR spectra were recorded on
a Bruker-AC 400 spectrometer. IR spectra were recorded on a
JASCO IR-700 spectrometer. Mass spectra were acquired on a
JEOL JMS-D 100 spectrometer. High-resolution mass spectra were
obtained on an AEI MS-9 double-focusing mass spectrometer and a
JEOL JMS-HX 110 spectrometer using the EI method.
3,4,6,7,8,8a-Hexahydro-2H-chromene (15)
Chromene 15 was prepared by the same method as that described
above for 11.
Yield: 0.17 g (60%).
IR (CH2Cl2): 3431, 3407, 3387, 1870, 1659, 1459 cm–1.
1H NMR (400 MHz, CDCl3): d = 5.46 (s, 1 H), 3.96–4.01 (m, 1 H),
3.85–3.88 (m, 1 H), 3.53 (td, J = 11.52, 2.68 Hz, 1 H), 1.64–2.17
(m, 10 H).
13C NMR (100 MHz, CDCl3): d = 136.09, 122.22, 74.75, 67.95,
31.92, 30.02, 28.14, 25.30, 20.54.
MS (EI): m/z (%) = 138 (20) [M+], 137 (100), 119 (63), 107 (51), 95
(55), 93 (89), 79 (51), 71 (100), 57 (83), 55 (63).
1-Oxaspiro[4.5]dec-6-ene (11);11 Typical Procedure
A soln of 1 (0.50 g, 2.55 mmol) in THF (10 mL) was added slowly
by syringe to 1.0 M DIBAL-H in cyclohexane (10 mL) at –78 °C.
The mixture was stirred at –78 °C for 1 h. A homogeneous soln was
obtained after slow addition of 6 M aq HCl (ca. 5.0 mL) to the mix-
ture and subsequent removal of the cooling bath. The mixture was
stirred for 10 min and diluted with Et2O (150 mL). The resultant
soln was washed with H2O (3 × 200 mL) and brine (3 × 200 mL),
dried (MgSO4; 10 g), filtered through a bed of Celite, and concen-
trated in vacuo. The residue was purified by column chromatogra-
phy (silica gel, hexanes–EtOAc, 10:1).
HRMS (EI) m/z calcd for C9H14O: 138.1045; found: 138.1041.
1-Oxaspiro[4.5]dec-6-en-2-one (16);14 Typical Procedure
CeCl3·7H2O (3.62 g, 9.72 mmol) and NaBH4 (1.23 g, 32.4 mmol)
were added separately in five portions to a stirring soln of 6 (0.50 g,
3.24 mmol) in MeOH (100 mL) at 0 °C. The mixture was stirred at
30 °C for 30 min, and the addition of 6 M aq HCl (5.0 mL) followed.
The mixture was stirred for 10 min and was concentrated in vacuo.
The residue was diluted with H2O (100 mL). The aqueous solution
was extracted with EtOAc (3 × 50 mL). The combined organic soln
was washed with H2O (3 × 200 mL) and brine (3 × 200 mL), dried
(MgSO4; 10 g), filtered through a bed of Celite, and concentrated in
vacuo. The residue was purified by column chromatography (silica
gel, hexanes–EtOAc, 5:1).
Yield: 0.29 g (82%).
IR (CH2Cl2): 3049, 2983, 1726, 1605, 1445 cm–1.
1H NMR (400 MHz, CDCl3): d = 5.77 (dt, J = 10.0, 3.7 Hz, 1 H),
5.58 (d, J = 10.0 Hz, 1 H), 3.81–3.88 (m, 2 H), 1.93–1.97 (m, 4 H),
1.61–1.78 (m, 4 H), 1.58–1.60 (m, 2 H).
13C NMR (100 MHz, CDCl3): d = 131.98, 128.98, 79.65, 67.02,
37.93, 34.97, 26.00, 24.97, 20.45.
1-Oxaspiro[5.5]undec-7-ene (12)12
Spiro ether 12 was prepared by the same method as that described
above for 11.
Yield: 0.15 g (67%).
IR (CH2Cl2): 3431, 3407, 3387, 2666, 1664 cm–1.
1H NMR (400 MHz, CDCl3): d = 5.94–5.98 (m, 1 H), 5.64 (d, J =
10.0 Hz, 1 H), 2.61 (t, J = 8.2 Hz, 2 H), 2.10–2.17 (m, 3 H), 1.96–
2.01 (m, 2 H), 1.81–1.85 (m, 1 H), 1.65–1.77 (m, 2 H).
Yield: 0.27 g (75%).
IR (CH2Cl2): 3531, 3431, 3388, 1667, 1438 cm–1.
1H NMR (400 MHz, CDCl3): d = 5.74–5.81 (m, 2 H), 3.61–3.69 (m,
2 H), 2.00–2.04 (m, 1 H), 1.90–1.93 (m, 1 H), 1.79–1.84 (m, 1 H),
1.67–1.74 (m, 1 H), 1.59–1.66 (m, 2 H), 1.46–1.53 (m, 6 H).
13C NMR (100 MHz, CDCl3): d = 176.67, 132.56, 128.45, 83.56,
34.53, 34.03, 28.72, 24.56, 19.30.
13C NMR (100 MHz, CDCl3): d = 130.42, 129.84, 69.93, 61.26,
1-Oxaspiro[4.4]non-6-en-2-one (17)8,14,15
Bicyclic lactone 17 was prepared by the same method as that de-
scribed above for 16.
35.69, 32.90, 25.89, 25.63, 18.93, 18.48.
1-Oxaspiro[4.4]non-6-ene (13)13
Spiro ether 13 was prepared by the same method as that described
above for 11.
Yield: 0.18 g (40%).
IR (CH2Cl2): 3856, 3431, 3387, 1774, 1663, 1459 cm–1.
Yield: 0.18 g (66%).
IR (CH2Cl2): 3493, 3407, 3388, 1851, 1663, 1365 cm–1.
1H NMR (400 MHz, CDCl3): d = 5.87–5.89 (m, 1 H), 5.66–5.68 (m,
1 H), 3.83 (t, J = 6.75 Hz, 2 H), 2.44–2.50 (m, 1 H), 2.24–2.31 (m,
1 H), 1.93–1.99 (m, 3 H), 1.83–1.89 (m, 3 H).
1H NMR (400 MHz, CDCl3): d = 6.08–6.10 (m, 1 H), 5.72–5.75 (m,
1 H), 2.60–2.64 (m, 3 H), 2.39–2.42 (m, 1 H), 2.21–2.30 (m, 3 H),
2.04–2.06 (m, 1 H).
13C NMR (100 MHz, CDCl3): d = 176.54, 137.44, 131.74, 97.74,
36.26, 33.44, 31.11, 29.68.
13C NMR (100 MHz, CDCl3): d = 134.73, 133.25, 93.91, 66.97,
3,4,6,7,8,8a-Hexahydro-2H-chromen-2-one (18)
Chromenone 18 was prepared by the same method as that described
above for 16.
36.60, 36.38, 30.80, 26.19.
6-Oxaspiro[4.5]dec-1-ene (14)11,13
Spiro ether 14 was prepared by the same method as that described
above for 11.
Yield: 0.13 g (44%).
IR (CH2Cl2): 3856, 3432, 3387, 2867, 1667, 1560, 1438 cm–1.
Yield: 0.24 g (72%).
IR (CH2Cl2): 3856, 3431, 3406, 1870, 1655 cm–1.
1H NMR (400 MHz, CDCl3): d = 5.89–5.93 (m, 2 H), 3.71–3.76 (m,
1 H), 3.64–3.69 (m, 1 H), 2.45–2.52 (m, 1 H), 2.24–2.32 (m, 1 H),
1.94–2.00 (m, 1 H), 1.86–1.92 (m, 1 H), 1.53–1.73 (m, 6 H).
1H NMR (400 MHz, CDCl3): d = 2.72 (s, 1 H), 4.82 (s, 1 H), 2.43–
2.74 (m, 4 H), 2.04–2.15 (m, 3 H), 1.72–1.81 (m, 2 H), 1.55–1.60
(m, 1 H).
13C NMR (100 MHz, CDCl3): d = 172.48, 130.56, 126.15, 76.03,
30.47, 29.10, 25.84, 24.90, 19.55.
13C NMR (100 MHz, CDCl3): d = 134.39, 133.68, 87.15, 63.43,
34.96, 34.53, 30.74, 25.84, 20.89.
MS (EI): m/z (%) = 152 (83) [M+], 124 (55), 110 (23), 97 (45), 96
(58), 91 (36), 82 (61), 79 (72), 67 (100), 55 (92).
HRMS (EI): m/z calcd for C9H12O2: 152.0837; found: 152.0840.
Synthesis 2006, No. 21, 3621–3624 © Thieme Stuttgart · New York