54%; mp 134È136 ¡C). IR (KBr): l \ 3415, 3230, 1735, 1635,
1620, 1400, 1255, 1175, 1120, 1050, 1020, 920, 835, 800 cm~1.
spectrum at 50 MHz, CDCl , spectrum contains artifacts):
3
d \ 15.37 and 21.23 (4-Me, 2@-Me), 75.38 (C-1@)*, 81.95 (C-3@)
1H NMR (300 MHz): d \ 1.93 (d, 4J
\ 1.1, 2@-Me), 2.58
\ 5.1, 1@-H), 5.10
**, 84.56 (C-5)**, 118.23 (C-3), 144.28 (C-2@), 167.47 (C-4),
173.20 (C-2); *assignment analogous to compound ul-29
2{vMe, 3{
\ J
1{, OH 1{, 5
(d, J
\ 4.5, OH), 4.27 (dd, J
OH, 1{
(ddd, J
5, 1{
5.7, 4J \ 1.9, 3-H), 6.49 (br s, 3@-H), 7.35 (dd, J \ 5.9,
3, 5 4, 3
\ 6.0, J \ 4J \ 1.9, 5-H), 6.20 (dd, J
\
(d
Cv1{
(294.1) calcd. C 36.76, H 3.77; found C 36.68, H 3.84.
\ 75.38); **assignments interchangeable. C H IO
5, 4
5, 3
3, 4
9
11 3
J
\ 1.7, 4-H). 13C NMR (APT spectrum at 50 MHz,
4, 5
CDCl ): d \ 20.83 (2@-Me), 76.89 (C-1@), 82.30 (C-3@)*, 84.40
lk-5-[E-5-(3-Furanyl)-1-hydroxy-2-methyl-2-penten-4-
3
(C-5)*, 123.06 (C-3), 144.70 (C-2@), 152.71 (C-4), 171.74 (C-2);
ynyl]-3-methyl-2(5H)-furanone. lk-32 (72.3 mg, 70%) was pre-
pared from iodide lk-29 (117.6 mg, 0.400 mmol), CuI (9.5 mg,
*assignments interchangeable. C H IO (280.1) calcd. C 34.31,
8
9
3
H 3.24; found C 34.13, H 3.18.
0.050 mmol, 0.10 equiv.), Pd(PPh ) (28.9 mg, 0.0250 mmol, 5
3 4
mol%), alkyne 12 (5.63 wt% in THF, 785 mg, 0.481 mmol, 1.2
equiv.) and (Pri) NEt (1 ml) as described for the synthesis of
ul-5-(E-1-Hydroxy-3-iodo-2-methyl-2-propenyl)-2(5H)-
2
lk-33. IR (KBr): l \ 3440, 3020, 1755, 1215, 1165, 1065, 870,
furanone (ul-30). At [78 ¡C ZnBr (2.25 g, 10.0 mmol, 1.0
2
760, 670 cm~1. 1H NMR (400 MHz): d \ 1.96 (dd, 4J
\
equiv.) was added to a solution of siloxyfuran 15 (1.56 g, 10.0
3vMe, 4
\ 1.1, 2@-Me), 2.40 (d,
5J
\ 1.8, 3-Me), 2.04 (d, 4J
mmol) and aldehyde 13 (1.96 g, 10.0 mmol, 1.0 equiv.) in
3vMe, 5
\ 3.9, OH), 4.12 (dd, J
1{, 5
2{vMe, 3{
J
\ 6.4, J
\ 4.2, , 1@-H),
CH Cl (10 ml). After stirring for 2.5 h at this temperature,
OH, 1{
1{, OH
2
2
4.97 (dqd, J
\ 6.6, 5J
5, 3vMe
B J B 2.0, 5-H), 5.78 (br s,
aqueous NaHCO solution (4 ml) was added and the reaction
5, 1{
5, 4
3
3@-H), 6.46 (d, J
\ 1.4, 4A-H), 6.96 (hardly resolved qd,
mixture allowed to warm to room temperature. Work-up as
4_, 5_
4J
B J B 1.5, 4-H), 7.40 (dd, J
\ 4J
\ 1.7,
described for lk-30 including Ñash chromatography (2.5 cm,
light petroleumÈtert-BuOMe 2 : 1 until F18, then 1 : 1) a†ord-
ed ul-30 (1.174 g, 42%; mp 104È106 ¡C) in the early fractions
and lk-30 (258 mg, 9%) in the late fractions. IR (KBr):
l \ 3415, 3095, 2915, 1765, 1620, 1600, 1335, 1270, 1170, 1105,
1045, 910, 890, 815, 725, 710 cm~1. 1H NMR (300 MHz):
4, 3vMe
4, 5
5_, 4_
5_, 2_
5A-H), 7.63 (br s, 2A-H). 13C NMR (100 MHz gated-decoupled
and 100 MHz DEPT spectrum, respectively; DEPT-CH and
2
3
CH signals in italics, CDCl ): d \ 10.78, 15.88 (2@-CH and
3
3
3-CH ), 77.06 (C-1@)*, 82.80 (C-5)*, 86.21, 87.42 (C-4@ and C-5@),
3
107.59 (C-3A), 109.25, 112.38 (C-4A and C-3@), 131.72 (C-3)**,
142.94, 145.11, 145.34 (C-2A, C-4 and C-5A), 146.61 (C-2@),
d \ 1.92 (d, 4J
\ 0.7, 2@-Me), 3.16 (br s, OH), 4.43 (d,
2{vMe, 3{
\ 4.9, 1@-H), 5.09 (ddd, J
5, 1{
5-H), 6.18 (dd, J \ 5.6, 4J \ 1.9, 3-H), 6.51 (qd of which
3, 4 3, 5
only the three central tips are visible, 4J
173.54 (C-2); *assignments interchangeable; **assignment
J
\ 5.3, J \ 4J \ 1.7,
5, 4 5, 3
1{, 5
analogous to compound lk-29 (d \ 129.71). C
H
O
Cv3
15 14
4
(258.3) calcd. C 69.76, H 5.46; found C 69.69, H 5.71.
B 4J
B 1.1,
3{, 2{vMe
5{, 1{
3@-H), 7.47 (dd, J \ 5.7, J \ 1.6, 4-H). 13C NMR (APT
4, 3
4, 5
3
ul-5-[E-5-(3-Furanyl)-1-hydroxy-2-methyl-2-penten-4-
spectrum at 50 MHz, CDCl ): d \ 21.15 (2@-Me), 75.03 (C-1@),
ynyl]-3-methyl-2(5H)-furanone. ul-32 (78.4 mg, 76%) was pre-
pared from iodide ul-29 (117.6 mg, 0.40 mmol, 1.0 equiv.), CuI
81.72 (C-3@)*, 83.54 (C-5)*, 122.93 (C-3), 144.50 (C-2@), 153.50
(C-4), 173.07 (C-2); *assignments interchangeable. C H IO
8
9
3
(9.5 mg, 0.050 mmol, 0.1 equiv.), Pd(PPh ) (28.9 mg, 0.0250
(280.1) calcd. C 34.31, H 3.24; found C 34.10, H 3.02.
3 4
mmol, 5 mol%), alkyne 12 (5.63 wt% in THF, 785.2 mg, 0.480
mmol, 1.2 equiv.) and (Pri) NEt (1 ml) as described for com-
2
lk-5-(E-1-Hydroxy-3-iodo-2-methyl-2-propenyl)-4-methyl-
pound lk-33 (mp 125È126 ¡C). IR (KBr): l \ 3375, 3145, 1730,
2(5H)-furanone. lk-31 (1.36 g, 46%; mp 102È103 ¡C) was pre-
pared from siloxyfuran 16 (1.70 g, 10.0 mmol), aldehyde 13
(1.96 g, 10.0 mmol, 1.0 equiv.) and BF É OEt (1.27 ml, 1.42 g,
1400, 1160, 1110, 1065, 875, 785 cm~1. 1H NMR (400.13
MHz): d \ 1.95 (qd of which only the central tips are resolv-
ed, 4J
(d, J
B 5J
B 1.5, 3-Me), 2.04 (br s, 2@-CH ), 2.44
3
2
3vMe, 4
3vMe, 5
3
10.0 mmol, 1.0 equiv.) as described for lk-29. IR (KBr):
l \ 3415, 1845, 1745, 1645, 1435, 1395, 1325, 1260, 1185, 1160,
1110, 1055, 980, 925, 870, 760, 665 cm~1. 1H NMR (300
MHz): d \ 1.96 and 2.13 (2 d which were hardly resolved,
\ 3.9, OH), 4.44 (hardly resolved dd, J
B
OH, 1{
B 3.3, 1@-H), 4.99 (dqd, J
5, 1{
1{, OH
J
\ 4.4, 5J
B J B 1.8,
1{, 5
5, 3vMe
5, 4
5-H), 5.90 (br s, 3@-H), 6.46 (d, J
\ 1.5, 4A-H), 7.06 (hardly
4_, 5_
resolved qd, 4J
B J B 1.3, 4-H), 7.40 (dd, J
\
4, 3vMe
4, 5
5_, 4_
4J \ 0.8 and 0.7, respectively, 4-Me, 2@-Me), 2.72 (d, J
\
4J
\ 1.4, 5A-H), 7.63 (br s, 2A-H). 13C NMR (100 MHz
OH, 1{
5_, 2_
7.9, OH), 4.39 (br dd, J
5-H), 5.89 (qd, 4J
\ 7.8, J
\ 2.5, 1@-H), 4.97 (m ,
gated-decoupled and 100 MHz DEPT spectrum, respectively;
1{, OH
1{, 5
c
\ 4J \ 1.5, 3-H), 6.53 (hardly
DEPT-CH and CH signals in italics, CDCl ): d \ 10.74,
3, 4vMe
3, 5
2
3
3
resolved qd, 4J
\ 4J
\ 1.1, 3@-H). 13C NMR (APT
16.39 (2@-CH and 3-CH ), 74.60 (C-1@)*, 81.64 (C-5)*, 86.15,
3{, 2{vMe
3{, 1{
3
3
spectrum at 50 MHz, CDCl ; spectrum contained artifacts):
87.64 (C-4@ and C-5@), 107.71 (C-3A), 108.22, 112.43 (C-4A and
C-3@), 131.89 (C-3)**, 142.98, 145.21, 145.31 (C-2A, C-5A and
C-4), 146.60 (C-2@), 174.05 (C-2); *assignments interchange-
3
d \ 14.26 and 21.55 (4-Me, 2@-Me), 73.90 (C-1@)*, 81.19 (C-3@)
**, 85.19 (C-5)**, 118.20 (C-3), 145.28 (C-2@), 166.58 (C-4),
173.14 (C-2); *assignment made because of shift analogy to
able; **assignment analogous to lk-29 (d \ 129.71).
Cv3
lk-29
(d
\ 74.84);
**assignments
interchangeable.
C
H
O
(258.3) calcd. C 69.76, H 5.46; found C 69.88, H
C~1{
15 14
4
C H IO (294.1) calcd. C 36.76, H 3.77 found C 36.74, H
5.64.
9
11
3
3.79.
lk-5-[E-5-(3-Furanyl)-1-hydroxy-2-methyl-2-penten-4-
ul-5-(E-1-Hydroxy-3-iodo-2-methyl-2-propenyl)-4-methyl-
2(5H)-furanone. ul-31 (1.27 g, 44%, mp 114È115 ¡C), along
with lk-30 (318 mg, 11%; separated as the late fractions of the
Ñash chromatography), was prepared from siloxyfuran 16
(1.70 g, 10.0 mmol), aldehyde 13 (1.96 g, 10.0 mmol, 1.0 equiv.)
ynyl]-2(5H)-furanone (lk-33). A solution of alkyne 12 (27.8
wt% in THF, 16.6 mg, 0.500 mmol, 1.25 equiv.) in (Pri) NEt (1
2
ml) was added dropwise to a suspension of iodide lk-30 (112.0
mg, 0.3999 mmol, 1.0 equiv.), CuI (9.5 mg, 0.050 mmol, 0.1
equiv.) and PdCl (PPh ) (17.5 mg, 0.0249 mmol, 5 mol%) in
2
3 2
and ZnBr (2.25 g, 10.0 mmol, 1.0 equiv.) as described for the
THF (4 ml). After stirring for 30 min a saturated aqueous
2
synthesis of ul-30. IR (KBr): l \ 3410, 3100, 1845, 1780, 1650,
solution of NH Cl (5 ml) was added. The organic layer was
4
1435, 1395, 1380, 1330, 1260, 1185, 1160, 1110, 1055, 980, 925,
separated and the aqueous layer extracted with CH Cl
2
2
870, 760, 665 cm~1. 1H NMR (300 MHz): d \ 1.93 and 2.10
(4 ] 10 ml). The combined organic layers were dried over
(2 br s, 4-Me, 2@-Me), 2.85 (d, J
\ 4.5, OH), 4.47 (br dd,
MgSO . After removal of the solvent in vacuo, Ñash chroma-
OH, 1{
\ 4.4, 1@-H), 4.99 (br d, J
1{, OH 5, 1{
4
J
\ J
\ 4.2, 5-H), 5.86
tography (1.5 cm, light petroleumÈtert-BuOMe 4 : 1 until F13,
1{, 5
(qd of which only the three central tips are visible, 4J
\
then 1 : 3, d14È24) provided lk-33 (66.4 mg, 68%; mp 132È
134 ¡C). IR (Ðlm): l \ 3435, 1755, 1345, 1185, 1165, 1115,
1085, 1045, 1010, 940, 920, 870, 840, 790, 780, 725 cm~1. 1H
3, 4vMe
4J \ 1.5, 3-H), 6.56 (qd of which only the three central tips
3, 5
are visible, 4J
\ 4J
\ 1.2, 3@-H). 13C NMR (APT
3{, 2{vMe
3{, 1{
New J. Chem., 2000, 24, 659È669
667