2128 J . Org. Chem., Vol. 62, No. 7, 1997
Oku et al.
ethylation.19 Overall yields of diazo ketones from the corre-
sponding starting esters were 1 (44%), 9 (52%), 19 (54%), 26
(48%), and 31 (41%).
NuH (0.706 mmol, 1.3 equiv) and diazo ketone (0.50 mmol)
dissolved in CH2Cl2 (3.0 mL) at one time under an argon
atmosphere at ambient temperature. The reaction mixture
was stirred for 30 min, in general, until the diazo ketone was
not detectable on a TLC plate. After workup with 8 mL of
saturated aqueous NaHCO3 solution, the solvent was removed
and the residue was chromatographed through a flash column,
in general, on silica gel or basic alumina in the cases where
certain products 4a , 10, 30a , 33, and 36a were proved labile
on silica gel. Some products (17 and 18) were isolated by
distillation under vacuum.
Spectroscopic data of diazo ketones and the corresponding
precursors are as follows.
2-[(E t h oxyca r b on yl)m et h yl)-2-m et h yld ioxola n e: 1H
NMR (300 MHz, CDCl3) 1.19 (t, J ) 7.2 Hz, 3H), 1.42 (s, 3H),
2.59 (s, 2H), 3.90 (s, 4H), 4.07 (q, J ) 7.2 Hz, 2H); IR (liquid
film) 1740 (s) cm-1. 2-(Ca r boxym eth yl) a n a logu e: 1H NMR
(300 MHz, CDCl3) 1.48 (s, 3H), 2.69 (s, 2H), 3.97 (s, 4H), 10.15
(brs, 1H); IR (liquid film) 2400-3400 (br), 1720 (s) cm-1
.
2-(3′-Diazo-2′-oxopr opyl)-2-m eth yldioxolan e (1): 1H NMR
(300 MHz, CDCl3) 1.39 (s, 3H), 2.63 (s, 2H), 3.94-3.97 (m, 4H),
5.46 (s, 1H); 13C NMR (75.6 MHz, CDCl3) 24.2, 50.5, 55.6, 64.6,
Spectroscopic data of the products are as follows.
3-Meth yl-4,7-d ioxoca n -2-en -1-on e (3):11 1H NMR (300
MHz, CDCl3) 1.98 (s, 3H), 3.94-3.98 (m, 2H), 4.05 (s, 2H),
4.14-4.17 (m, 2H), 5.01 (s, 1H); 13C NMR (75.6 MHz, CDCl3)
23.4, 67.6, 72.2, 74.7, 100.9, 168.7, 201.3; IR (liquid film) 1740
(s), 1620 (s) cm-1; HRMS (EI) calcd for C7H10O3 (M+) 142.0629,
found 142.0633.
107.8, 190.8; IR (liquid film) 2100 (s), 1640 (s) cm-1
.
2-[2′-(E t h oxyca r b on yl)et h yl]-2-m et h yld ioxola n e: 1H
NMR (300 MHz, CDCl3) 1.24 (t, J ) 7.2 Hz, 3H), 1.31 (s, 3H),
2.00 (d, J ) 7.5 Hz, 1H), 2.02 (d, J ) 7.8 Hz, 1H), 2.36 (d, J )
7.8 Hz, 1H), 2.40 (d, J ) 7.5Hz, 1H) 3.90-3.95 (m, 4H), 4.12
(q, J ) 7.2 Hz, 2H); IR (liquid film) 1740 (s) cm-1. 2′-Ca r boxy
a n a logu e: 1H NMR (300 MHz, CDCl3) 1.33 (s, 3H), 2.03 (d, J
) 7.2 Hz, 1H), 2.05 (d, J ) 7.8 Hz, 1H), 2.43 (d, J ) 7.8 Hz,
1H), 2.45 (d, J ) 7.2, 1H), 3.90-4.00 (m, 4H), 10.58 (brs, 1H);
7-Acet oxy-7-m et h yl-3,6-d ioxoca n -1-on e (4a ): 1H NMR
(300 MHz, CDCl3) 1.70 (s, 3H), 2.06 (s, 3H), 3.01 (d, J ) 11.4
Hz, 1H), 3.58-3.72 (m, 3H), 3.84 (d, J ) 18.3 Hz, 1H), 4.15 (d,
J ) 18.3 Hz, 1H), 4.22-4.31 (m, 1H); 13C NMR (75.6 MHz,
CDCl3) 22.0, 24.4, 45.9, 64.3, 73.4, 78.5, 104.3, 168.9, 211.0;
IR (liquid film) 2400-3400 (br), 1720 (s) cm-1
.
IR (liquid film) 1740 (s), 1720 (s) cm-1
.
2-(4′-Dia zo-3′-oxobu tyl)-2-m eth yld ioxola n e (9): 1H NMR
(300 MHz, CDCl3) 1.32 (s, 3H), 1.99-2.04 (m, 2H), 2.40-2.44
(m, 2H), 3.89-3.99 (m, 4H), 5.24 (brs, 1H); 13C NMR (75.6
MHz, CDCl3) 23.6, 33.4, 35.0, 54.1, 64.4, 108.9, 194.4; IR (liquid
7-Meth oxy a n a logu e 4b: 1H NMR (300 MHz, CDCl3) 1.34
(d, J ) 0.9 Hz, 3H), 2.38 (d, J ) 11.1 Hz, 1H), 3.21 (s, 3H),
3.46-3.62 (m, 2H), 3.60 (d, J ) 11.1 Hz, 1H), 3.81 (dd, J )
0.3, 18.3 Hz, 1H), 3.93-3.99 (m, 1H), 4.17 (d, J ) 18.3 Hz,
1H), 4.24-4.29 (m, 1H); 13C NMR (75.6 MHz, CDCl3) 21.9,
47.7, 48.4, 62.4, 73.8, 78.9, 100.2, 212.2; IR (liquid film) 1750
(s), 1380 (s), 1220 (s), 1170 (s) cm-1; HRMS (EI) calcd for
C8H14O4 (M+) 174.0891, found 174.0900.
film) 2100 (s), 1640 (s) (m) cm-1
.
1
2-[3′-(Eth oxyca r bon yl)p r op yl]-2-m eth yld ioxola n e: H
NMR (300 MHz, CDCl3) 1.22 (t, J ) 7.2 Hz, 3H), 1.29 (s, 3H),
1.60-1.76 (m, 4H), 2.29 (t, J ) 7.2 Hz, 2H), 3.85-3.95 (m, 4H),
4.09 (q, J ) 7.2 Hz, 2H); IR (liquid film) 1740 (s) cm-1
. 3′-
7-Acetoxy-7-m eth yl-3,6-d ioxon a n -1-on e (10): 1H NMR
(300 MHz, CDCl3) 1.72 (s, 3H), 2.02 (s, 3H), 2.29-2.34 (m, 1H),
2.44-2.47 (m, 1H), 2.63 (d, J ) 10.8 Hz, 1H), 2.70 (d, J ) 10.8
Hz, 1H), 3.64-3.75 (m, 4H), 4.00 (d, J ) 15.6 Hz, 1H), 4.11 (d,
J ) 15.6 Hz, 1H); 13C NMR (75.6 MHz, CDCl3) 22.1, 22.3, 34.7,
34.9, 64.1, 72.9, 81.6, 106.7, 169.3, 210.7; IR (liquid film) 1730
ca r boxy a n a logu e: 1H NMR (300 MHz, CDCl3) 1.32 (s, 3H),
1.66-1.79 (m, 4H), 2.36-2.40 (m, 2H), 3.88-3.98 (m, 4H); IR
(liquid film) 2400-3700 (br), 1710 (s) cm-1
.
2-(5′-Dia zo-4′-oxop en tyl)-2-m eth yld ioxola n e (19): 1H
NMR (300 MHz, CDCl3) 1.30 (s, 3H), 1.62-1.77 (m, 4H), 2.35-
2.39 (m, 2H), 3.89-3.94 (m, 4H), 5.24 (brs, 1H); 13C NMR (75.6
MHz, CDCl3) 19.6, 23.7, 38.2, 40.7, 54.3, 64.6, 109.7, 194.8;
(s), 1720 (s) cm-1
.
1
2-(4′-Acetoxy-3′-oxobu tyl)-2-m eth yld ioxola n e (11): H
NMR (300 MHz, CDCl3) 1.31 (s, 3H), 2.00 (d, J ) 7.2 Hz, 1H),
2.03 (d, J ) 7.5 Hz, 1H), 2.16 (s, 3H), 2.47 (d, J ) 7.5 Hz, 1H)
2.49 (d, J ) 7.2 Hz, 1H), 3.86-3.97 (m, 4H), 4.67 (s, 2H); 13C
NMR (75.6 MHz, CDCl3) 20.5, 23.9, 32.4, 33.4, 64.7, 67.9,
IR (liquid film) 2100 (s), 1640 (s) cm-1
.
2-[(Eth oxyca r bon yl)m eth yl]-2-m eth yl-1,3-d ioxa n e: 1H
NMR (300 MHz, CDCl3) 1.23 (t, J ) 7.2 Hz 3H), 1.52 (s, 3H),
1.63-1.73 (m, 2H), 2.77 (s, 2H), 3.84-3.97 (m, 4H), 4.12 (q, J
) 7.2 Hz, 2H); IR (liquid film) 1740 (s) cm-1
. 2-Ca r b oxy
109.0, 170.3, 203.4; IR (liquid film) 1750 (s), 1725 (s) cm-1
;
a n a logu e: 1H NMR (300 MHz, CDCl3) 1.56 (s, 3H), 1.56-1.66,
(m, 1H), 1.84-1.98, (m, 1H), 2.78 (s, 2H), 3.91-4.06 (m, 4H);
HRMS (CI) calcd for C10H17O5 (MH+) 217.1075, found 217.1065.
1
4′-Meth oxy a n a logu e (11a ): H NMR (300 MHz, CDCl3)
IR (liquid film) 2400-3700 (br), 1720 (s) cm-1
.
1.32 (s, 3H), 2.01 (t, J ) 7.2 Hz, 4H), 2.51 (t, J ) 7.2 Hz, 2H),
3.41 (s, 3H), 3.90-3.95 (m, 4H), 4.03 (s, 2H); 13C NMR (75.6
MHz, CDCl3) 23.7, 32.2, 33.2, 59.1, 64.5, 77.3, 109.0, 208.0;
IR (liquid film) 1720 (s) cm-1; HRMS (CI) calcd for C9H17O4
(MH+) 189.1126, found 189.1119.
(ter t-Bu tyld im eth ylsilyl)oxy d Er iva tive of 9-Hyd r oxy-
7-oxa n on a n e-2,5-d ion e (16a ). Because 16a and 16b were
not isolable in a pure state, an anomeric mixture of 16a and
16b was treated with tert-butyldimethylchlorosilane to be
converted to the corresponding silyloxy derivative and ana-
lyzed: 1H NMR (300 MHz, CDCl3) 0.06 (s, 6H), 0.88 (s, 9H),
2.17(s, 3H), 2.68-2.77 (m, 4H), 3.58 (d, J ) 5.7 Hz, 1H), 3.59
(d, J ) 5.1 Hz, 1H), 3.77 (d, J ) 5.1 Hz, 1H), 3.79 (d, J ) 5.7
Hz, 1H), 4.15 (s, 2H); 13C NMR (75.6 MHz, CDCl3) -5.4, 18.3,
25.8, 29.8, 32.4, 36.5, 62.7, 73.1, 76.5, 206.8, 208.0; IR (liquid
film) 1720 (s) cm-1; HRMS (CI) calcd for C14H29O4Si (MH+)
289.1834, found 289.1834.
2-(3′-Dia zo-2′-oxop r op yl)-2-m eth yl-1,3-d ioxa n e (26): 1H
NMR (300 MHz, CDCl3) 1.50 (s, 3H), 1.50-1.58 (m, 1H), 1.81-
1.92 (m, 1H), 2.70 (s, 2H), 3.84-4.01 (m, 4H), 5.53 (bs, 1H);
13C NMR (75.6 MHz, CDCl3) 20.3, 25.2, 50.7, 55.3, 59.6, 97.8,
190.6; IR (liquid film) 2100 (s), 1640 (s) cm-1
.
2-[2′-(Eth oxyca r bon yl)eth yl]-2-m eth yl-1,3-d ioxa n e: 1H
NMR (300 MHz, CDCl3) 1.25 (t, J ) 7.2 Hz, 3H), 1.39 (s, 3H),
1.50-1.60 (m, 1H), 1.71-1.84 (m, 1H), 2.00-2.06 (m, 2H),
2.41-2.46 (m, 2H), 3.81-3.96 (m, 4H), 4.11 (q, J ) 7.2 Hz,
2H); IR (liquid film) 1735 (s) cm-1
. 2′-Ca r boxy a n a logu e:
1H NMR (300 MHz, CDCl3) 1.43 (s, 3H), 1.47-1.56 (m, 1H),
1.79-1.91 (m, 1H), 2.00 (d, J ) 7.2 Hz, 1H), 2.03 (d, J ) 7.5
Hz, 1H), 2.53, (dd, J ) 4.5, 7.5 Hz, 1H), 2.56 (dd, J ) 4.5, 7.2
Hz, 1H), 3.83-4.01 (m, 4H); IR (liquid film) 2400-3700 (br),
1720 (s) cm-1
.
2-(4′-Dia zo-3′-oxobu tyl)-2-m eth yl-1,3-d ioxa n e (31): 1H
NMR (300 MHz, CDCl3) 1.32 (d, J ) 3.0 Hz, 3H), 1.45-1.52
(m, 1H), 1.62-1.78 (m, 1H), 1.93 (dd, J ) 3.0, 8.0 Hz, 1H),
1.96 (dd, J ) 3.0, 8.0 Hz, 1H), 2.39 (br, 2H), 3.73-3.90 (m,
4H), 5.23 (brs, 1H); 13C NMR (75.6 MHz, CDCl3) 20.6, 25.3,
33.5, 34.8, 54.2, 59.7, 98.3, 195.0; IR (liquid film) 2100 (s), 1640
4-Meth ylen e-5,8-dioxon an -1-on e (18): 1H NMR (300 MHz,
C6D6) 2.15-2.19 (m, 2H), 2.32-2.36 (m, 2H), 3.12 (t, J ) 4.2
Hz, 2H), 3.45 (t, J ) 4.2 Hz, 2H), 3.70 (s, 2H), 3.81 (d, J ) 1.5
Hz, 1H), 4.00 (d, J ) 0.6 Hz, 1H); 1H NMR (300 MHz, in CDCl3)
2.50-2.60 (m, 4H), 3.75 (d, J ) 4.5 Hz 1H), 3.77 (d, J ) 3.6
Hz, 1H), 4.03 (d, J ) 3.6 Hz, 1H), 4.03 (s, 2H), 4.05 (d, J ) 4.5
(s) cm-1
.
Hz, 1H), 4.08 (d, J ) 1.8Hz, 1H), 4.26 (d, J ) 1.8 Hz, 1H); 13
C
Gen er a l P r oced u r e of Rh 2(OAc)4-Ca ta lyzed Rea ction
of Dia zo Keton es. To a CH2Cl2 solution (10 mL) of Rh2(OAc)4
(2.2 mg, 1.0 mol % equivalent) were added a protic nucleophile
NMR (75.6 MHz, CDCl3) 33.2, 35.0, 71.9, 73.0, 81.9, 89.3,
164.1, 210.7; IR (liquid film) 1730 (s), 1710 (s), 1645 (m) cm-1
.
HRMS (EI) calcd for C8H12O3 (M+) 156.0786, found 156.0794.
Another isomer 17 was unstable under chromatographic
conditions and, therefore, unable to be isolated. However,
(19) Padwa, A.; Fryxell, G. E.; Zhi, L. J . Am. Chem. Soc. 1990, 112,
3100.