820
M. Markovič et al.
PAPER
Rf = 0.4 (hexanes–EtOAc, 19:1).
IR (ATR): 2929, 2858, 1054, 835, 776, 653 cm–1.
1H NMR (300 MHz, CDCl3): δ = 0.13 (s, 3 H, SiMe), 0.14 (s, 3 H,
SiMe), 0.91 (s, 9 H, t-Bu), 1.74–1.70 (m, 3 H, H-6), 2.48 (d, J = 2.2
Hz, 1 H, H-1), 4.86–4.81 (m, 1 H, H-3), 5.55 (ddq, J = 15.2, 5.7, 1.6
Hz, 1 H, H-4), 5.82 (dqd, J = 15.0, 6.5, 1.3 Hz, 1 H, H-5).
1.50 g/1 mmol of olefin) and the mixture was warmed to r.t. over a
period of 1 h. The reaction mixture was extracted with EtOAc
(3 × 30 mL), and the combined organic extracts were washed with
brine (30 mL), dried over MgSO4, filtered and concentrated in vac-
uo. Purification of the residue by flash chromatography on silica gel
(hexanes–EtOAc, 100:0 to 80:20; then isocratic hexanes–EtOAc,
80:20) provided 0.44 g of the desired racemic mixture of diastereo-
mers (xylo/lyxo) in 76% yield as a pale yellow oil; Rf = 0.2
(hexanes–EtOAc, 4:1).
13C NMR (151 MHz, CDCl3): δ = –4.6, –4.4, 17.6, 18.1, 26.0, 63.4,
73.1, 84.3, 129.1, 129.7.
HRMS (ESI): m/z [M + H]+ calcd for C12H23OSi: 211.15182;
found: 211.15118.
(2R,3S,4S)-Hex-5-ene-2,3,4-triol (D-xylo-9) and
(2R,3S,4R)-Hex-5-ene-2,3,4-triol (D-lyxo-9)
To a stirred solution of diastereomeric mixture D-xylo-8/D-lyxo-8
(1.33 g, 5.44 mmol, 1 equiv) and but-1-en-3-ol (0.78 g, 10.89 mmol,
2 equiv) in MeOH (50 mL) was added Lindlar catalyst (130 mg, 10
wt % according to the mixture of alkynes). The flask was three
times evacuated and filled with hydrogen via balloon and the mix-
ture was left to vigorously stir at r.t. under hydrogen atmosphere
(balloon) until full conversion (detected by TLC). The mixture was
then filtered through fiberglass filter paper which was followed by
addition of Dowex® 50W X8 (10.00 g) to the filtrate. The reaction
mixture was stirred until full conversion (TLC), and then was fil-
tered and concentrated in vacuo. Purification of the residue by flash
chromatography on silica gel (hexanes–EtOAc, 100:0 to 0:100; then
EtOAc) provided 0.61 g of the desired mixture of diastereomers
(2R,3S,4S)-4-(tert-Butyldimethylsilyloxy)hex-5-yne-2,3-diol
(D-xylo-8) and (2R,3S,4R)-4-(tert-Butyldimethylsilyloxy)hex-5-
yne-2,3-diol (D-lyxo-8)
A suspension of AD-mix-β (57.89 g, 1.40 g/1 mmol of olefin) and
MeSO2NH2 (3.93 g, 41.35 mmol, 1 equiv) in H2O (207 mL) and t-
BuOH (207 mL) was stirred at r.t. until both phases became clear.
Then, the mixture was cooled to 0 °C, whereupon the inorganic salts
partially precipitated, and tert-butyl(hex-4-en-1-yn-3-yloxy)di-
methylsilane (7; 8.70 g, 41.35 mmol, 1 equiv) was added in one por-
tion. The resulting heterogeneous slurry was stirred overnight, the
reaction was quenched at 0 °C by addition of sodium sulfite (62.03
g, 1.50 g/1 mmol of olefin) and the mixture was warmed to r.t. over
a period of 1 h. The reaction mixture was extracted with EtOAc
(3 × 250 mL), and the combined organic extracts were washed with
brine (200 mL), dried over MgSO4, filtered and concentrated in vac-
uo. Purification of the residue by flash chromatography on silica gel
(hexanes–EtOAc, 100:0 to 80:20; then isocratic hexanes–EtOAc,
80:20) provided 9.31 g of the desired mixture of diastereomers
1
(D-xylo/D-lyxo, 40:60 from H NMR data) in 85% yield over two
steps as a pale yellow oil.
D-xylo-9
Rf = 0.2 (EtOAc).
1H NMR (300 MHz, CDCl3): δ = 1.28 (d, J = 6.4 Hz, 3 H, H-1),
2.84–2.74 (br s, 2 H, OH), 2.89 (br s, 1 H, OH), 3.30 (t, J = 3.6 Hz,
1 H, H-3), 3.95 (qd, J = 6.4, 3.4 Hz, 1 H, H-2), 4.28–4.21 (m, 1 H,
H-4), 5.27 (dt, J = 10.5, 1.4 Hz, 1 H, H-6a), 5.38 (dt, J = 17.3, 1.5
Hz, 1 H, H-6b), 5.94 (ddd, J = 17.2, 10.5, 5.9 Hz, 1 H, H-5).
1
(D-xylo/D-lyxo, 40:60 from H NMR data) in 92% yield as a pale
yellow oil.
D-xylo-8
Rf = 0.2 (hexanes–EtOAc, 4:1).
13C NMR (75 MHz, CDCl3): δ = 20.2, 68.8, 74.5, 76.6, 117.3,
137.6.
HRMS (ESI): m/z [M + H]+ calcd for C6H13O3: 133.08647; found:
133.08585; m/z [M + Na]+ calcd for C6H12NaO3: 155.06841; found:
155.06771.
1H NMR (300 MHz, CDCl3): δ = 0.16 (s, 3 H, SiMe), 0.19 (s, 3 H,
SiMe), 0.91 (s, 9 H, t-Bu), 1.28 (d, J = 6.5 Hz, 3 H, H-1), 2.26 (br s,
1 H, OH), 2.49 (d, J = 2.1 Hz, 1 H, H-6), 2.75 (d, J = 5.0 Hz, 1 H,
OH), 3.45–3.33 (m, 1 H, H-3), 4.00 (m, 1 H, H-2), 4.44 (dd, J = 6.4,
2.1 Hz, 1 H, H-4).
13C NMR (75 MHz, CDCl3): δ = –5.0, –4.2, 18.3, 20.4, 25.9, 64.6,
66.9, 75.0, 76.0, 82.5.
HRMS (ESI): m/z [M + H]+ calcd for C12H25O3Si: 245.15730;
found: 245.15682; m/z [M + Na]+ calcd for C12H24NaO3Si:
267.13924; found: 267.13874.
D-lyxo-9
Rf = 0.2 (EtOAc).
1H NMR (300 MHz, CDCl3): δ = 1.23 (d, J = 6.5 Hz, 3 H, H-1),
1.78 (br s, 1 H, OH), 2.84–2.67 (br s, 1 H, OH), 2.89 (br s, 1 H, OH),
3.39 (t, J = 3.5 Hz, 1 H, H-3), 4.00 (qd, J = 6.5, 3.2 Hz, 1 H, H-2),
4.35–4.29 (m, 1 H, H-4), 5.28 (dt, J = 10.5, 1.5 Hz, 1 H, H-6a), 5.38
(dt, J = 17.3, 1.5 Hz, 1 H, H-6b), 5.93 (ddd, J = 17.3, 10.5, 5.8 Hz,
1 H, H-5).
D-lyxo-8
Rf = 0.2 (hexanes–EtOAc, 4:1).
1H NMR (300 MHz, CDCl3): δ = 0.16 (s, 3 H, SiMe), 0.19 (s, 3 H,
SiMe), 0.91 (s, 9 H, t-Bu), 1.24 (d, J = 6.5 Hz, 3 H, H-1), 2.52 (d,
J = 2.2 Hz, 1 H, H-6), 2.78 (d, J = 8.6 Hz, 1 H, OH), 2.85 (br s, 1 H,
OH), 3.43–3.35 (m, 1 H, H-3), 4.34 (‘q’, J = 6.4 Hz, 1 H, H-2), 4.55
(dd, J = 3.6, 2.2 Hz, 1 H, H-4).
13C NMR (75 MHz, CDCl3): δ = –5.2, –4.6, 18.2, 19.6, 25.8, 66.8,
67.2, 75.4, 77.6, 82.1.
13C NMR (75 MHz, CDCl3): δ = 19.7, 67.2, 75.5, 76.1, 117.3,
136.7.
(1S,5R,7R,8S)-8-(tert-Butyldimethylsilyloxy)-7-methyl-2,6-di-
oxabicyclo[3.3.0]octan-3-one (D-ido-10) and (1R,5S,7R,8S)-8-
(tert-Butyldimethylsilyloxy)-7-methyl-2,6-dioxabicyc-
lo[3.3.0]octan-3-one (D-galacto-10)
Procedure A
(±)-4-(tert-Butyldimethylsilyloxy)hex-5-yne-2,3-diol
(xylo-8/lyxo-8)
A 10-mL round-bottom flask equipped with a side inlet with stop-
cock was charged with the diastereomeric mixture of alkenetriols
D-xylo-9/D-lyxo-9 (40:60; 0.30 g, 2.28 mmol, 1 equiv), NaOAc
(0.56 g, 6.83 mmol, 3 equiv), anhydrous CuCl2 (0.92 g, 6.83 mmol,
3 equiv) and PdCl2 (0.04 g, 0.23 mmol, 0.1 equiv) in glacial AcOH
(9 mL). The flask was evacuated and filled with gaseous CO, and
the heterogeneous mixture was vigorously stirred at r.t. under CO
atmosphere (balloon) until its colour changed from green to pale
brown (overnight). The reaction mixture was concentrated in vacuo,
suspended in EtOAc (50 mL), filtered through a pad of silica gel and
concentrated in vacuo. The crude mixture of lactones was dissolved
A suspension of K3Fe(CN)6 (2.35 g, 7.13 mmol, 3 equiv), K2CO3
(0.99 g, 7.13 mmol, 3 equiv), K2[OsO2(OH)4] (3.50 mg, 9.50 μmol,
0.004 equiv), pyridine (18.80 mg, 0.24 mmol, 0.1 equiv) and
MeSO2NH2 (0.23 g, 2.38 mmol, 1 equiv) in H2O (12 mL) and t-
BuOH (12 mL) was stirred at r.t. until both phases became clear.
Then, the mixture was cooled to 0 °C, whereupon the inorganic salts
partially precipitated, and tert-butyl(hex-4-en-1-yn-3-yloxy)di-
methylsilane (7; 0.50 g, 2.38 mmol, 1 equiv) was added in one por-
tion. The resulting heterogeneous slurry was stirred overnight, the
reaction was quenched at 0 °C by addition of sodium sulfite (3.57 g,
Synthesis 2014, 46, 817–821
© Georg Thieme Verlag Stuttgart · New York