HETEROCYCLES, Vol. 72, 2007
417
for C14H31O7PSi: C, 45.39; H, 8.43. Found: C, 45.28; H, 8.54.
1
12a: H NMR ꢀ = 0.10, 0.12 (3H each, 2s, Me2Si), 0.91 (9H, s, Me3C), 1.38 (3H, d, JMe,H = 4.9 Hz,
MeCH), 3.82, 3.85 [3H each, 2d, JPOMe = 10.7 Hz, P(OMe)2], 3.84 (1H, m, H-2), 3.89 (1H, dd, J4R,4S
=
11.9, 4J4S,OH = 1.8, J4S,P = 0 Hz, HS-4), 3.99 (1H, ddd, J1,1’ = 11.6, J1’,2 = 2.8, J1’,P = 1.0 Hz, H’-1), 4.01
(1H, dd, J4R,P = 2.7 Hz, HR-4), 4.28 (1H, dd, J1,2 = 3.4 Hz, H-1), 4.75 (1H, q, MeCH), 5.05 (1H, dd, JOH,P
= 5.8 Hz, HO-3); 31P NMR ꢀ = 22.5.
4
1
12b: H NMR ꢀ = 0.10, 0.12 (3H each, 2s, Me2Si), 0.90 (9H, s, Me3C), 1.36 (3H, d, JMe,H = 4.9 Hz,
MeCH), 3.48 (1H, dd, J4S,P = 28.7, J4R,4S = 11.3 Hz, HS-4), 3.72 (1H, ddd, J2,P = 31.1, J1,2 = 9.2, J1’,2 = 5.5
Hz, H-2), 3.84 [6H, d, JPOMe = 10.7 Hz, P(OMe)2], 3.84 (1H, dd, J1,1’ = 9.7 Hz, H’-1), 4.13 (1H, br s, HO-
3), 4.18 (1H, t, H-1), 4.47 (1H, dd, J4R,P = 9.8 Hz, HR-4), 4.75 (1H, q, MeCH); 31P NMR ꢀ = 26.6.
1-O-(tert-Butyldimethylsilyl)-3-deoxy-3-dimethoxyphosphinoyl-2,4-O-ethylidene-D-erythritol (13a)
and its L-threitol epimer (13b).
Methyl oxalyl chloride (0.800 mL, 8.70 mmol) was added to a solution of 12a,b (923 mg, 2.49 mmol)
and DMAP (1.06 g, 8.68 mmol) in dry acetonitrile (20 mL) at 0 °C. The mixture was stirred at rt for 1 h
under argon, poured into water and then the most of solvent was distilled off in vacuo. The residue was
dissolved in CHCl3, washed with saturated NH4Cl and then water, dried (Na2SO4), and evaporated in
vacuo to give the 5-methoxalyloxy derivative as a pale yellow syrup: Rf = 0.28 (D).
The crude syrup was coevaporated with dry toluene and dissolved in the same solvent (15 mL).
Tributyltin hydride (1.10 mL, 4.09 mmol) and AIBN (80 mg, 0.49 mmol) were added under argon. The
mixture was stirred at 80 °C for 2 h and then concentrated in vacuo. The residue was separated by
column chromatography with a gradient eluant of 1:3 to 1:1 AcOEt–hexane to give 13a and 13b.
26
1
13a: Colorless syrup (608 mg, 69%); Rf = 0.24 (D); [ꢁ]D –22.5° (c 2.75); H NMR ꢀ = 0.06, 0.08 (3H
each, 2s, Me2Si), 0.89 (9H, s, Me3C), 1.30 (3H, d, JMe,H = 5.2 Hz, MeCH), 2.52 (1H, dddd, J3,P = 18.0,
J3,4S = 11.9, J2,3 = 10.1, J3,4R = 4.9 Hz, H-3), 3.73, 3.75 [3H each, 2d, JPOMe = 10.7 Hz, P(OMe)2], 3.81
(1H, td, J4R,4S = 11.6, J4S,P = 3.4 Hz, HS-4), 3.83 (2H, m, H’-1, H-2), 3.94 (1H, dd, J1,1’ = 10.1, J1,2 = 0.8
Hz, H-1), 4.24 (1H, ddd, J4R,P = 1.5 Hz, HR-4), 4.66 (1H, q, MeCH); 13C NMR ꢀ = –5.24, –4.97 (Me2Si),
18.46 (Me3C), 20.90 (d, 5JMe,P = 1.7 Hz, MeCH), 25.90 (Me3C), 33.00 (d, J3,P = 34.7 Hz, C-3), 52.43 (d,
JMe,P = 6.9 Hz, POMe), 52.61 (d, JMe,P = 6.3 Hz, POMe), 64.69 (C-1), 65.55 (d, J4,P = 1.7 Hz, C-4), 76.84
31
(d, J2,P = 2.9 Hz, C-2), 98.78 (MeCH); P NMR ꢀ = 27.6. Anal. Calcd for C14H31O6PSi: C, 47.44; H,
8.82. Found: C, 47.60; H, 8.71.
13b: Colorless syrup (160 mg, 18%); Rf = 0.16 (D); [ꢁ]D26 +15.4° (c 2.02); 1H-NMR ꢀ = 0.065, 0.07 (3H
each, 2s, Me2Si), 0.89 (9H, s, Me3C), 1.36 (3H, d, JMe,H = 5.2 Hz, MeCH), 1.99 (1H, dtd, J3,P = 19.5, J3,4S
= 3.4, J2,3 = 3.1, J3,4R = 1.1 Hz, H-3), 3.77, 3.79 [3H each, 2d, JPOMe = 10.7 Hz, P(OMe)2], 3.82–3.86 (2H,
m, H,H’-1), 3.88 (1H, ddd, J4S,P = 34.8, J4R,4S = 11.6 Hz, HS-4), 3.94 (1H, dddd, J2,P = 41.8, J1,2 = 7.1, J1’,2
13
= 5.1 Hz, H-2), 4.56 (1H, ddd, J4R,P = 9.3 Hz, HR-4), 4.73 (1H, q, MeCH); C NMR ꢀ = –5.33, –5.16
(Me2Si), 18.34 (Me3C), 20.95 (MeCH), 25.85 (Me3C), 34.87 (d, J3,P = 39.9 Hz, C-3), 52.08 (d, JMe,P = 6.3
Hz, POMe), 52.58 (d, JMe,P = 5.8 Hz, POMe), 64.60 (d, J1,P = 2.2 Hz, C-1), 67.44 (d, J4,P = 5.2 Hz, C-4),
31
78.90 (d, J2,P = 5.2 Hz, C-2), 100.21 (MeCH); P NMR ꢀ = 31.4. Anal. Calcd for C14H31O6PSi: C,