Notes
2-Meth yl-2-bu ten oic Acid , 1-Ben zyl Ester (12). To a
J . Org. Chem., Vol. 62, No. 5, 1997 1559
) 17.7), 5.03 (m, 2H), 2.93 (d, 2H, J ) 6.4), 1.30 (s, 6H): 13C
NMR (125 MHz) δ ) 24.9, 35.1, 82.7, 114.0, 116.6, 129.4, 136.0,
139.3, 144.4, 146.3.
solution of benzyl alcohol (1.62 g, 15 mmol) in CH2Cl2 (50 mL)
was added 4-(dimethylamino)pyridine (DMAP, 0.5 g, 4.1 mmol)
and 2-methyl-2-butenoic acid (1.5 g, 15 mmol). After 10 min,
dicyclohexyl carbodiimide (DCC, 3.9 g, 19 mmol) was added, and
the solution was stirred for 10 h. After removal of solvent at
reduced pressure, the residue was suspended in dry ether (75
mL) and filtered to remove insoluble urea. Concentration,
followed by flash chromatography on silica gel (10% EA/hex)
2-(Tr im eth ylsilyl)-3-h ydr oper oxy-2(Z)-n on en e (17). 2-(Tri-
methylsilyl)-2(Z)-nonene33 (113 mg, 0.57 mmol) was subjected
to dye-sensitized photooxygenation as described above to afford,
after flash chromatography (5 f 10% EA/hex), 62 mg (60% based
on recovered starting material) of the hydroperoxide: Rf ) 0.36
(10% EA/hex); 1H NMR (500 MHz): δ ) 7.77 (s, 1H), 5.84 (d,
1H, J ) 2.8), 5.57 (d, 1H, J ) 2.4), 4.52 (t, 1H, J ) 6.5), 1.6 -
1.27 (10H), 0.88 (t, 3H, J ) 6.5), 0.16 (s, 9H); 13C NMR (125
MHz) δ ) 152.4, 127.5, 91.0, 33.9, 32.3, 29.8, 26.5, 23.2, 14.7,
-0.12; IR (neat) 3411 cm-1; Anal. Calcd for C12H26SiO2: C, 62.6;
H, 11.3. Found: C, 62.4; H, 11.5.
1
afforded 2.65 g (93%) of the ester: Rf ) 0.47 (20% EA/Hex); H
NMR (300 MHz) δ ) 7.39-7.27 (m, 5H), 6.93 (dq, 1H, J ) 1.4,
7.2), 5.19 (s, 2H), 1.87 (t, 3H, J ) 1.2), 1.78 (dt, 3H, J ) 7.2,
1.2); 13C (75 MHz): δ ) 168.4, 138.2, 128.7, 128.6, 66.8, 35.6,
26.2, 25.3, 15.0, 12.7, IR (neat) 1712 cm-1
C
.
Anal. Calcd for
12H14O2: C, 75.8; H, 7.4. Found: C, 75.8; H, 8.2.
2-Meth ylen e-3-h yd r op er oxybu ta n oic Acid , Ben zyl Ester
Dioxygen a tion of 2-Meth yl-2-bu ten -1-ol. A solution of
2-methyl-2-buten-1-ol (237 mg, 2.75 mmol) in 10 mL of 0.001 M
solution TPP/CH2Cl2 was subjected to photooxygenation as
described above to afford, after flash chromatography (50% EA/
hex), 297 mg (95%) of an inseparable mixture of regioisomeric
hydroperoxides 18 and 19 which were characterized via HET-
COR and COSY experiments: Rf ) 0.29 (40% EA/hex); IR (neat)
(13). Benzyl tiglate (207 mg, 1.1 mmol) was subjected to dye-
sensitized photooxygenation as described above to furnish, after
flash chromatography on silica gel (10 f 20% EA/hex), 144 mg
1
(59%) of the hydroperoxide: Rf ) 0.21 (10% EA/hex); H NMR
(300 MHz): δ ) 8.80 (s, 1H), 7.38 (m, 5H), 6.42 (s, 1H), 5.97 (s,
1H), 5.23 (s, 2H), 5.03 (q, 1H, J ) 5.7), 1.36 (d, 3H, J ) 6.4); 13
C
3358 cm-1
118.0631.
.
HRMS calcd for C5H10O3 (M+) 118.0630, found:
NMR (75 MHz): δ ) 166.6, 141.2, 136.4, 129.3, 129.0, 128.8,
126.7, 80.1, 67.4, 19.2; IR (neat) 3403, 1713 cm-1. Anal. Calcd
for C12H14O4: C, 64.9; H, 6.4. Found: C, 63.9; H, 6.4.
3-Hyd r op er oxy-2-m eth ylen ebu ta n ol (18): 1H NMR (300
MHz): δ 5.26 (bs, 1H), 5.20 (bs, 1H), 4.65 (q, 1H, J ) 6.7), 4.19
(q, 2H, J ) 16.6), 1.27 (d, 3H, J ) 6.7); 13C NMR (75 MHz) δ )
148.1, 116.9, 83.8, 63.3, 18.2.
1,1,4-Tr im eth yl-2(E),4-p en ta d ien yl Hyd r op er oxid e (14).
2,5-Dimethyl-2,4-hexadiene (77.3 mg, 0.7 mmol) dissolved in
CH2Cl2 (5 mL) was added via a precooled syringe to a -78 °C
solution of the ozonide generated from (+)-4. The solution was
stirrred at -78 °C for 90 min. The solvent was removed in
vacuo. Flash chromatography on silica gel (10% EA/hex) gave
23 mg (23%) of the tertiary hydroperoxide: Rf ) 0.22 (10% EA/
hex); 1H NMR (300 MHz): δ ) 7.67 (s, 1H), 6.33 (d, 1H, J )
16.2), 5.73 (d, 1H, J ) 16.2), 5.02 (m, 2H), 1.84 (d, 3H, J ) 0.7),
1.38 (s, 6H); 13C NMR (75 MHz): δ ) 142.0, 133.8, 133.4, 127.2,
118.1, 25.1, 19.1; IR (neat) 3397 cm-1; Anal. Calcd for C8H1402:
C, 67.6; H, 9.9. Found: C, 65.5, H, 9.6.
2-Hyd r op er oxy-2-m eth yl-3-bu ten -1-ol (19): 1H NMR (300
MHz): δ 9.5 (bs, 1H), 5.90 (dd, 1H, J ) 17.9, 11.2), 5.27 (bd,
1H, 17.9), 5.24 (bd, 1H, J ) 11.4), 3.69 (q, 2H, J ) 11.9), 1.27 (s,
3H); 13C NMR (75 MHz) δ ) 138.5, 117.4, 83.4, 66.2, 19.9.
Ack n ow led gm en t. This research was supported by
the American Cancer Society (CN-34). NMR spectrom-
eters used in this research were purchased, in part, with
funds from the NIH Shared Instrumentation Program
(SIG-1-510-RR06307); we are grateful to Prof. Richard
Shoemaker for assistance with NMR experiments.
Dioxygen a tion of m yr cen e resulted in an inseparable 1:1
mixture of 15:16. Rf ) 0.36 (10% EA/hex); IR (neat) 3413 cm-1
.
The two compounds could be characterized via HETCOR and
COSY NMR experiments on the mixture:
Su p p or t in g In for m a t ion Ava ila b le: 1H and 13C NMR
spectra for 5, 12, 13, 14, a mixture of 15/16, 17, and a mixture
of 18/19 (14 pages). This material is contained in libraries on
microfiche, immediately follows this article in the microfilm
version of the journal, and can be ordered from the ACS; see
any current masthead page for ordering information.
4-Meth ylen e-1-(1-m eth yleth en yl)-5-h exen yl h yd r op er -
oxid e (15): 1H NMR (500 MHz): δ ) 8.54 (s, 1H), 6.34 (dd,
1H, J ) 17.7, 10.5), 5.20 (d, 2H, J ) 17.7), 5.03 (m, 2H), 5.0 (d,
2H, J ) 1.2), 4.32 (t, 1H, J ) 6.9), 2.23 (m, 2H), 1.71 (t, 3H, J )
1.2), 1.68 (m, 2H); 13C NMR (125 MHz) δ ) 17.8, 28.0, 30.1, 89.7,
114.0, 114.8, 116.6, 139.3, 144.4, 144.6.
1,1-Dim eth yl-5-m eth ylen e-2,6-h ep ta d ien yl (16): 1H NMR
(500 MHz): δ ) 8.01 (s, 1H), 6.34 (dd, 1H, J ) 17.7, 10.5), 5.72
(dt, 1H, J ) 15.7,6.9), 5.60 (dt, 1H, J ) 15.7,1.2), 5.20 (d, 2H, J
J O961564H
(33) Eisch, J . J .; Damasevitz, G. A. J . Org. Chem. 1976, 41, 2214.