Chloromethanesulfonylethene and Dichloromethanesulfonylethene: New Reagents for Tandem Diels-Alder/Ramberg-Baecklund Reactions

Article abstract of DOI:10.1021/ol0363523

(Matrix presented) Chloromethanesulfonylethene (3a) and dichloromethanesulfonylethene (3b) were prepared by oxidation of the adducts of ethylene and ClCH₂-SCl or Cl₂CHSCl, respectively, followed by NaHCO₃ dehydrochlorinati

Full text of DOI:10.1021/ol0363523

1
Supporting Information
Chloromethanesulfonylethene and Dichloromethanesulfonylethene: New Reagents
for Tandem Diels-Alder-Ramberg-Bäcklund Reactions
Eric Block*, Hak Rim Jeon, Shao-Zhong Zhang, and Evgeny Dikarev
b-Chlorosulfides may be toxic on inhalation, ingestion or skin contact. These compounds should
only be handled in a well-ventilated hood using rubber gloves. All glassware used should be
rinsed with bleach (“Clorox”) immediately after use.
2
ClCH SCl
4
Chloromethanesulfenyl Chloride (5) . A magnetic stirrer-equipped flask was charged with
o
CH
Cl
2 2
(60 mL) and Me
2
S
2
(9.16 g, 97 mmole), the mixture was cooled to –78 C and Cl
2
gas
was bubbled through slowly using a 9 mm glass tube (a solid was formed plugging smaller bore
tubes). The mixture turned red-orange and a colorless solid (CH SCl ) appeared. The mixture
3
3
turned into a milky, yellow-white slurry, which continued to thicken and lighten until the
solution became saturated with chlorine, at which time the mixture took on a yellow-green color.
Addition of Cl
2
was stopped and a reflux condenser with drying tube was fitted to the flask.
SCl was promoted by warming the flask to room temperature. An orange
Decomposition of CH
3
3
liquid formed as HCl was evolved. Concentration in vacuo yielded the title compound as a
1
malodorous, lachrymatory oil (20 g, 88%) which was used without further purification; H NMR
13
(
3 3
300 MHz, CDCl ) d 5.12 (s); C NMR (75 MHz, CDCl ) d 54.8.

2
2 2 2
ClCH CH SCH Cl
5
1
-Chloro-2-chloromethanesulfanylethane (6) . Chloromethanesulfenyl chloride (19.2 g, 17.8
mmol) and CH
Cl
2 2
(200 mL) were placed in a flask fitted with a gas inlet tube and a drying tube.
o
Ethylene gas was slowly introduced at 0 C until the starting material disappeared as indicated by
1
H NMR analysis. Concentration in vacuo afforded the known title compound as a yellow oil
(21.4 g, 90 %) which was used directly for the next step without further purification; bp 99-100
o
1
C (15 mm); H NMR (300 MHz, CDCl
3
) d 4.75 (s, 2H), 3.76 (t, J = 7.8 Hz, 2H), 3.11 (t, J = 7.8
) d 49.2, 42.4, 34.0; GC-MS m/z (relative intensity) 146
M , Cl, 14), 144 (M , Cl, 20), 111 (23), 109 (63), 95 (51), 45 (100).
CH =CHSO CH Cl
Chloromethanesulfonylethene (3a). m-Chloroperbenzoic acid (77 %, 107 g, 0.47 mole) was
added to a solution of 1-chloro-2-chloromethanesulfanylethane (30.8 g, 0.21 mole) in CH Cl
750 mL) over 30 min at room temperature and the mixture was stirred for 16 h. The colorless
13
Hz, 2H); C NMR (75 MHz, CDCl
3
+
37
+ 35
(
2
2
2
2
2
(
precipitate was removed by filtration and excess aqueous NaHCO
3
was added to the filtrate
which was stirred for 16 h. The reaction mixture was washed with H
3 ´ 200 mL), and the organic phase was separated, dried (Na SO
affording the title compound as a colorless oil (29.4 g, 99 %); see footnote 8 for nmr data; IR
2
O (3 ´ 200 mL) and brine
(
2
4
) and concentrated in vacuo
-
1
(
CHCl
ClCH CH
-Chloro-2-(dichloromethanesulfanyl)ethane (9). A three-necked round bottom flask was
3
) 1149, 1325 (SO
2
) cm .
2
2
SCHCl
2
1
2 2 2 2
charged with Me S (10 mL, 113 mmol) and CH Cl (120 mL). The solution was cooled to - 78
o
C and Cl
2
gas was bubbled through slowly for 3-5 min. The reaction mixture turned reddish
SCl ). The slurry continued to thicken until the
, at which time the mixture took on a yellow-green color and
orange and a colorless solid precipitated (CH
3
3
solution had been saturated with Cl
2

3
the addition of Cl
2
was stopped. The reaction mixture was warmed to room temperature and
stirred for 1 h to give a bright orange solution with the release of HCl gas, which was absorbed
o
with aqueous NaOH solution. The orange solution was cooled to -78 C and Cl
2
gas was bubbled
through again. As before, a colorless solid precipitated. The slurry continued to thicken until the
solution had been saturated with Cl , at which time the mixture took on a yellow-green color and
the addition of Cl was stopped. The reaction mixture was warmed to room temperature, stirred
2
2
2 2
for 1 h, concentrated in vacuo and diluted with CH Cl (300 mL). The solution was cooled to 0
o
C and ethylene gas was bubbled in through a glass tube until the color of the solution lightened.
Concentration in vacuo afforded the title compound as a yellow oil (37.2 g; 91%). The product
1
was used directly for the next step without further purification; H NMR (300 MHz, CDCl
3
) d
) d
1
3
6
3
.83 (s, 1H), 3.84 (t, J = 7.3 Hz, 2H), 3.33 (t, J = 7.3 Hz, 2 H); C NMR (75 MHz, CDCl
4.1, 42.5, 73.9 (d, J = 12.6 Hz).
3
CH
Dichloromethanesulfonylethene (3b). m-Chloroperbenzoic acid (77 %, 27 g, 120 mmol) was
added to a solution of 1-chloro-2-dichloromethanesulfanylethane (9.0 g, 50 mole) in CH Cl
200 mL) over 30 min at 20 °C and the mixture was stirred for 16 h. The colorless precipitate
2 2 2
=CHSO CHCl
2
2
(
was removed by filtration The filtrate was concentrated and the residue chromatographed (silica
gel; 6:1 hexane/EtOAc). The so-purified 1-chloro-2-(dichloromethanesulfonyl)ethane was
dissolved in CH
detrimental) and stirred for 16 h. The mixture was washed with H
00 mL), dried (Na SO ), concentrated in vacuo, and chromatographed (silica gel; 5:1
hexane/EtOAc) to afford the title compound as a low melting solid, mp 50-51 °C (7.5 g, 86%);
Cl
2 2
3 3
(200 mL), mixed with 1.1 eq. of aqueous NaHCO (excess NaHCO is
2
O (2 ´ 100 mL) and brine (2 ´
1
2
4
-1
-1
see footnote 8 for nmr data; IR (CHCl
3 2
) 1145, 1348 cm (SO ), 948, 3020 cm (C=C). Anal.
Calcd. for C Cl S: C, 20.59; H, 2.30. Found: C, 20.46; H, 2.07.
3
H
4
2 2
O

4
2 2
CH =CHSCH Cl
Chloromethanesulfanylethene (11). Triisopropylsilanol (0.1 mL, 0.5 mmol) was added to a
slurry of pulverized KOH (6.93 g, 0.12 mole) in tetraethyleneglycol dimethyl ether (150 mL) and
the mixture was stirred at room temperature for 1 h. 1-Chloro-2-chloromethanesulfanylethane
(2.91 g, 59 mmol) was added to the mixture and the color changed from yellow to dark brown.
The mixture was stirred at 20 °C until the starting material had disappeared as indicated by TLC
(
7:1 hexane/EtOAc, ca. 1.5 h). The mixture was then distilled into a liquid nitrogen cooled trap
0.02 Torr). The title compound was separated as a colorless oil from the colorless precipitate
(
using a syringe (4.38 g, 69 %). See footnote 8 for spectroscopic data.
ClCH SCHClCH SCH Cl
-Chloro-1,2-bis(chloromethanesulfanyl)ethane (12). Chloromethanesulfanylethene (3.03 g,
2
2
2
1
o
2
2 2 2
8 mmol) was added to ClCH SCl (3.28 g, 28 mmol) in CH Cl (50 mL) at 0 C. The reaction
mixture was stirred at room temperature for 1 h and concentrated in vacuo affording the title
compound as a yellow oil (5.78 g, 96 %). The product was used directly without further
1
purification; H NMR d 5.53 (t, J = 6.5 Hz, 1H), 4.98 and 4.80 (AB
q
, J = 11.2 Hz, 2H), 4.78 (s,
13
2
H), 3.41 (d, J = 6.9 Hz, 2H); C NMR: d 64.4, 49.3, 46.7, 38.9; GC-MS m/z (rel. inten.), 227
+
37
+ 35
(
M , Cl, 10), 225 (M , Cl, 29), 108 (94), 97 (43), 95 (100).
ClCH SCH=CHSCH Cl
E,Z)-1,2-Bis(chloromethanesulfanyl)ethene (13). 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU,
2
2
(
1
.66 mL, 11 mmol) was added to a solution of 1,2-bis(chloromethanesulfanyl)-1-chloroethane
o
(1.42 g, 5.5 mmol) in CHCl
3
(50 mL) at 0 C and the reaction mixture was heated to reflux for 1
h. The reaction progress was monitored by GC. The organic layer was washed with 0.5 N HCl (2
25 mL), NaHCO solution (2 ´ 25 mL), brine (2 ´ 25 mL), dried (Na SO ) and concentrated in
´
3
2
4

5
vacuo. Distillation gave the title compound as a light yellow oil (0.61 g, 58 %; E/Z 1.3/1). See
footnote 8 for spectroscopic data.
ClCH
E,Z)-1,2-Bis(chloromethanesulfonyl)ethene ((E,Z)-4). Dimethyldioxirane (100 mL, 0.09 M)
was added to a solution of 1,2-bis(chloromethanesulfanyl)ethene (0.4 g, 2.1 mmol) in CHCl (5
mL) at room temperature and the reaction mixture was stirred at room temperature overnight.
The resulting mixture was dried (Na SO ) and concentrated under reduced pressure. The residue
was subjected to column chromatography (hexanes/EtOAc 3/2) affording both the (E)-isomer (R
.8, 0.15 g, 28 %) and the (Z)-isomer (R 0.6, 0.11 g, 20 %) as colorless solids. (E)-1,2-
bis(chloromethanesulfonyl)ethene: Anal. Calcd. for C Cl : C, 18.98; H, 2.39. Found: C,
9.37; H, 2.06. See footnote 8 for additional physical and spectroscopic data.
2 2 2 2
SO CH=CHSO CH Cl
(
3
2
4
f
0
f
4
H
6
2 4 2
O S
1
SO CH Cl
2
2
3
-Chloromethanesulfonyldibenzobicyclo[2.2.2]octadiene. A mixture of anthracene (1.35 g,
7
.14 mmol) and chloromethanesulfonylethene (0.5 g, 3.57 mmol) in toluene (1.5 mL) was heated
o
in a sealed tube at 155 C for 7 h. The reaction mixture was taken up in CHCl
3
(30 mL),
anthracene (0.15 g) was removed by filtration, the filtrate was concentrated in vacuo and the
3
residue chromatographed (1:1 pentane/CHCl , then CHCl
3
) gave the title compound as a
o
-
colorless solid (1.12 g, 96 %), mp 143-145 C; IR (film) 1322 (SO
2
), 1146 (SO
2
), 1118 (SO
2
) cm
1
1
;
q
H NMR d 7.46-7.16 (m, 8H), 5.00 (d, J = 2.1 Hz, 1H), 4.86 (t, J = 2.7 Hz, 1H), 4.16 (AB , J =
1
3
1
1
2.7, 2H), 3.74 (ddd, J = 2.4, 6.3, 9.3 Hz, 1H), 2.30-2.26 (m, 2H); C NMR d 143.3, 143.2,
40.9, 137.9, 127.1, 127.1, 126.6, 126.5, 125.6, 124.0, 124.0, 123.6, 59.5, 55.6, 43.5, 43.3, 30.2;
2
Anal. Calcd for C17H15ClO S: C, 64.04; H, 4.74. Found C, 63.69; H, 4.98.

6
3
-Methylenedibenzobicyclo[2.2.2]octadiene. A solution of t-BuOK in THF (4.08 mL, 4.08
mmol, 1 M) was added to 3-chloromethanesulfonyldibenzobicyclo[2.2.2]octadiene (0.67 g, 2.04
o
mmol) in THF (10 mL) at 0 C. The reaction mixture was heated at reflux for 1 h, concentrated
in vacuo, and the residue was treated with ether (20 mL) and water (20 mL). The aqueous layer
was extracted with ether (2 ´ 20 mL), organic phase washed with water (2 ´ 20 mL), dried
10b
(
MgSO
4
), and concentrated in vacuo, affording the known title compound as colorless crystals
o
o
10b
1
(
0.39 g, 89 %), mp 104-105 C (lit. mp 101-10 2 C ); H NMR d 7.51-7.29 (m, 8H), 5.35 (br s,
1
3
1
1
H), 4.94 (d, J = 10.2 Hz, 2H), 4.55 (m, 1H), 2.65 (m, 2H); C NMR d 146.5, 143.4, 142.5,
+
26.2, 123.7, 123.6, 107.4, 107.4, 55.5, 45.0, 35.4; GC m/z (rel. inten.) 218 (M , 28), 178 (100).
SO CHCl
2
2
2
-Dichloromethanesulfonyl-1,2,3,4,5,6,7,8-octahydronaphthalene. A solution of dichloro-
methanesulfonylethene (1.0 g, 5.7 mmol) and 1,2-dimethylenecyclohexane (1.23 g, 11.4 mmol)
o
in toluene (2 mL) was heated to 80-100 C in a sealed tube overnight. The mixture was then
concentrated in vacuo and chromatographed (silica gel; 5:1 hexane/EtOAc) yielding the title
o
1
compound (1.52 g, 94%) as colorless crystals, mp 91-93 C.; H NMR (300 MHz, CDCl
3
) d
1
.40- 1.52 (m, 2 H), 1.62-1.75 (m, 2 H), 1.80-1.90 (m, 5 H), 2.03-2.11 (m, 2H), 2.15-2.30 (m, 2
13
H), 2.42 (t, J = 12.6 Hz, 1 H), 3.75-3.85 (m, 1 H), 6.27 (s, 1H); C NMR (75 MHz, CDCl
3
) d
-
1
2
1.8, 22.8, 29.1, 29.8, 30.0, 55.5, 124.5, 128.4; IR (CHCl
S: C, 46.65; H, 5.69. Found: C, 46.81; H, 5.32.
3 2
) 1140, 1322 cm (SO ). Anal. Calcd.
2 2
for C11H16Cl O

7
CH
3 2 3
SO CCl
Methyl Trichloromethyl Sulfone. Dimethyl sulfone (1.5 g, 15.9 mmol) and SO
Cl
2 2
(150 mL)
were placed in a photoreactor fitted with a Hanovia 450 watt UV lamp, wrapped with nichrome
heating wire, and containing at the bottom a gas bubbling tube and topped by a condenser. The
mixture was electrically heated to a gentle reflux as Cl
solution was irradiated for 2.5 h while monitoring TLC. The mixture was then concentrated in
vacuo, collecting the SO Cl for further use. The residue was chromatographed (silica gel; 5:1
hexane/EtOAc) giving the known title compound as colorless crystals (2.86 g, 91 %), mp 163-
2
was slowly introduced. The refluxing
2
2
11
1
13
1
65 °C; H NMR (300 MHz, CDCl
3
) d 3.35 (s, 3 H); C NMR (75 MHz, CDCl
3
) d 33.4, 103.1.
CCl2
2
-Dichloromethylene-1,2,3,4,5,6,7,8-octahydronaphthalene. A solution of 2-dichloromethane-
sulfonyl-1,2,3,4,5,6,7,8-octahydronaphthalene (566 mg, 2.0 mmol) and trichloromethanesulfo-
o
nylmethane (742 mg, 4.0 mmol) in THF (15 mL) was cooled to 0 C under Ar. A solution of
KOtBu in THF (1 M, 4.0 mL, 4.0 mmol) was added dropwise. The reaction mixture was stirred
o
for 1 h at 0 C and was quenched with saturated aqueous NH
4
Cl. The mixture was extracted with
4
ether (2 ´ 20 mL), dried (MgSO ), concentrated in vacuo and chromatographed (silica gel;
1
hexane) yielding the title compound (150 mg, 65%) as a colorless oil; H NMR (300 MHz,
3
CDCl ) d 1.59-1.63 (m, 4 H), 1.83-1.88 (m, 4 H), 2.02 (t, J = 6.5 Hz, 2 H), 2.51 (t, J = 6.5 Hz, 2
13
H), 2.79 (s, 2 H). C NMR (75 MHz, CDCl
3
) d 22.9, 28.5, 29.7, 29.8, 29.9, 30.4, 35.7, 111.6,
+
+
1
25.7, 128.4, 135.5. EIMS: m/z 218 (M + 2, 62), 216 (M , 93), 181 (100), 145 (80), 117 (30), 91
-1
-1
(
2
55). IR (neat): 715 cm (CCl ), 1643, 1664 cm (C=C).

8
SO CH Cl
2
2
H
H
SO CH Cl
2
2
5
-exo-6-endo-Bis(chloromethanesulfonyl)bicyclo[2.2.1]hept-2-ene
distilled cyclopentadiene (0.21 mL, 2.6 mmol) was added to a suspension of(E)-1,2-bis(chloromethanesulfo-
nyl)ethene (0.33 g, 1.3 mmol) in CH Cl (4 mL) and the reaction mixture was stirred at room
(15a).
Freshly
2
2
temperature until a colorless clear solution was obtained (ca. 10 min). Concentration in vacuo
followed by chromatography of the residue afforded the title compound as a colorless solid (0.35
o
-1 1
g, 83 %), mp 144-145 C; IR (film) 1322 (SO
2
), 1149 (SO
dd, J = 3.00, 5.4 Hz, 1H), 6.39 (dd, J = 3.00, 5.4 Hz, 1H), 4.75 (d, J = 8.4 Hz, 1H), 4.71 (d, J =
.4 Hz, 1H), 4.57 (d, J = 12.6 Hz, 1H), 4.44 (dd, J = 3.3, 5.1 Hz, 1H), 4.42 (d, J = 12.6 Hz, 1H),
2 2
), 1121 (SO ) cm ; H NMR d 6.44
(
8
3
1
3
13
.73 (dd, J = 2.1, 5.1 Hz, 1H), 3.52 (m, 2H), 2.03 and 1.71 (AB
q
, J = 9.6 Hz, 2H); C NMR d
36.8, 136.2, 61.1, 60.5, 56.4, 56.2, 47.6, 46.6, 45.2. Anal. Calcd. for C
9 2 4 2
H12Cl O S
: C, 33.86; H,
.79. Found: C, 33.51; H, 3.09.
H
H
SO CH Cl
2
2
SO CH Cl
2
2
5
-endo-6-endo-Bis(chloromethanesulfonyl)bicyclo[2.2.1]hept-2-ene (15b). Freshly distilled
cyclopentadiene (0.1 mL, 1.2 mmol) was added to a suspension of (Z)-1,2-bis(chloromethanesul-
fonyl)ethene (0.15 g, 0.6 mmol) in CH Cl (4 mL) and the reaction mixture was stirred at room
2
2
temperature until a colorless clear solution was obtained (ca. 10 min). This was concentrated in
vacuo, and the residue chromatographed (hexanes/EtOAc 5/1) affording the title compound as a
o
-1 1
colorless solid (0.16 g, 84 %), mp 184-186 C; IR (film) 1331 (SO
2 2
), 1152 (SO ) cm ; H NMR
(
acetone-d ) d 6.50 (m, 2H), 5.14 and 4.98 (AB , J = 12.6 Hz, 4H), 4.79 (m, 2H), 3.82 (m, 2H),
6
q

9
13
1
.76 and 1.65 (AB
q
, J = 9.0 Hz, 2H); C NMR (acetone-d
6
) d 130.9, 60.3, 53.4, 43.7, 42.8. Anal.
Calcd. for C O S : C, 33.86; H, 3.79. Found: C, 33.72; H, 3.48.
9
H
12Cl
2 4 2
SO CH Cl
2
2
SO CH Cl
2
2
2
-(1,2-Bis(chloromethanesulfonyl)ethyl-6,6-dimethylbicyclo[3.1.1]hept-2-ene (18) . A
mixture of (E)-1,2-bis(chloromethanesulfonyl)ethene (0.57 g, 2.25 mmol) and b-pinene (0.64 g,
.67 mmol) in toluene (1.5 mL) were placed in a sealed tube and flushed with argon. The white
4
o
o
slurry was heated at 135 C for 1.5 h, concentrated in vacuo (60 C), and the residue chromato-
graphed (hexanes/EtOAc 5/1) yielding the title compound as a colorless solid (0.63 g, 72 %), mp
o
-1 1
1
08-110 C; IR (film) 1323 (SO
AB , J = 12.6 Hz, 2H), 4.45 and 4.77 (AB
H), 2.74-2.82 (m, 1H), 2.40-2.50 (m, 2H), 2.26-2.28 (m, 2H), 2.01-2.12 (m, 2H), 1.88 (s, 3H),
2
), 1122 (SO
2
) cm ; H NMR d 5.09-5.51 (m, 1H), 4.63 and 4.77
(
q
q
, J = 12.6 Hz, 2H), 4.01-4.13 (m, 2H), 3.29-3.35 (m,
1
1
3
4
13
.15 (d, J = 9 Hz, 1H), 0.83 (s, 3H); C NMR d 141.9, 123.1, 57.2, 55.9, 52.0, 47.6, 45.3, 40.3,
8.2, 36.5, 31.7, 31.5, 26.0, 21.1; Anal. Calcd. for C
3.39; H,5.78.
9 2 4 2
H12Cl O S : C, 43.29; H, 5.70. Found: C,
(
E)-2-Buta-1,3-dienyl-6,6-dimethyl-bicyclo[3.3.1]hept-2-ene (20) . A solution of
t-
BuOK in THF (3.1 mL, 3.1 mmol, 1 M) was added to b-pinene adduct (0.57 g, 1.46 mmol) in
o
THF (30 mL) at 0 C. The reaction mixture was heated to reflux for 1 h. The reaction was
4 3
quenched with NH Cl solution and extracted with CHCl (5 ´ 30 mL). The organic layer was

1
0
washed with brine (2 ´ 30 mL), dried (MgSO
4
), concentrated in vacuo, and the residue was
1
chromatographed (hexanes) yielding the title compound (30 mg, 12 %) as a colorless oil: H
NMR d 6.39 (dd, J = 9.9, 16.8 Hz, 1H), 6.23 (d, J = 15.6 Hz, 1H), 6.01 (d, J = 15.6 Hz, 1H), 5.58
(s, 1H), 5.16 (d, J = 16.8 Hz, 1H), 5.01 (d, J = 9.9 Hz, 1H), 2.56 (m, 1H), 2.45-2.28 (m, 3H),
1
3
2
1
.01 (m, 1H), 1.32 (s, 3H), 1.12 (d, J = 8.7 Hz, 1H), 0.78 (s, 3H); C NMR d 146.5, 137.7,
34.6, 125.9, 125.5, 115.9, 41.0, 37.8, 32.2, 31.4, 29.7, 26.4, 21.1; GC/MS (relative intensity)
+
m/z 174 (M , 10), 131 (44), 91 (100), 77 (41); UV (CH
2 2
Cl ) l max 278 nm.
Elemental analysis for other Diels-Alder adducts
2
-Chloromethanesulfonyl-1,2,3,4,5,6,7,8-octahydronaphthalene (Table 1, entry 4 Diels-Alder
adduct). Calcd. for C11 S C, 53.11; H, 6.89. Found, C, 52.78; H, 6.50.
-Chloromethanesulfonyl-1,2,3,4,5,6,7,8,9,10-decahydroanthracene (Table 1, entry 5 Diels-
Alder adduct): Calcd. for C15 S: C, 59.88; H, 7.04; Found: C, 60.16; H, 6.65.
-(Dichloromethanesulfonyl)-1,2-dimethylcyclohexene (Table 1, entry 6 Diels-Alder adduct):
Calcd for C S: C, 42.03; H, 5.49. Found C, 42.21; H, 5.16.
-(Dichloromethanesulfonyl)bicyclo[2.2.2]oct-2-ene (Table 1, entry 7 Diels-Alder adduct):
Calcd. for C S: C, 42.36; H, 4.74. Found: C, 42.41; H, 5.10.
-exo-6-endo-Bis(chloromethanesulfonyl)bicyclo[2.2.1]hept-2-ene (15a): Calcd. for
: C, 33.86; H, 3.79. Found: C, 33.51; H, 3.09.
-endo-6-endo-Bis(chloromethanesulfonyl)bicyclo[2.2.1]hept-2-ene (15b): Calcd. for
: C, 33.86; H, 3.79. Found: C, 33.72; H, 3.48.
H
17ClO
2
2
H
21ClO
2
4
9 2 2
H14Cl O
5
9 2 2
H12Cl O
5
9 2 4 2
C H12Cl O S
5
9 2 4 2
C H12Cl O S