ACCEPTED MANUSCRIPT
(101 MHz, CDCl3) δ 156.2, 136.6, 134.0, 128.5, 128.2, 128.1, 117.8, 69.1, 66.7, 61.5, 54.3,
39.1, 25.9, 25.8, 18.1, −4.3, −4.9, −5.3, −5.4; HRMS (EI+) [(M)+] m/z calcd for
C26H47NO4Si2 493.3044; found 493.3040.
4.3. Benzyl (5R,6R)-5-allyl-2,2,3,3,9,9,10,10-octamethyl-4,8-dioxa-3,9-disilaundecan-6-
yl(benzyl)carbamate (14)
NaH (0.254 g, 5.81 mmol), BnBr (0.69 ml, 5.81 mmol), and TBAI (0.72 g, 1.94 mmol) were
added to solution of 8 (0.96 g, 1.94 mmol) in THF (20 ml) at 0 °C. The reaction mixture was
stirred at room temperature for 12 h, and then saturated aqueous NH4Cl was added. The
organic layer was separated and the aqueous layer was extracted with EtOAc. The combined
organic layer was washed with brine, dried with MgSO4, and filtered. The filtrate was
concentrated in vacuo. Purification using silica gel column chromatography gave compound
14 as a colorless oil; [α]2D5 −7.9 (c 1.0, CHCl3); IR (neat) ν max 3724, 3705, 3680, 3632, 3623,
3598, 3566, 2953, 2925, 2855, 2360, 2341, 2293, 1704, 1461, 1252, 1219, 835, 773, 670
cm−1; 1H NMR (400 MHz, CDCl3) δ 7.04‒7.43 (m, 10H), 5.65‒6.00 (m, 1H), 4.92‒5.23 (m,
4H), 4.49‒4.84 (m, 2H), 3.99‒4.25 (m, 2H), 3.51‒3.83 (m, 2H), 2.17‒2.52 (m, 2H), 0.81‒
13
0.93 (m, 18H), −0.14‒0.12 (m, 12H); C NMR (101 MHz, CDCl3) δ 157.1, 136.6, 134.3,
128.2, 128.1, 127.8, 126.9, 126.4, 117.4, 72.0, 67.2, 61.9, 49.9, 39.1, 37.1, 30.1, 29.7, 25.9,
25.8, 18.1, 18.0, 14.1, −4.4, −4.8, −5.6; HRMS (EI+) [(M)+] m/z calcd for C33H53NO4Si2
583.3513; found 583.3513.
4.4 General procedure for the ozonolysis of aldehydes 8 and 14
Ozone was bubbled through a solution of 8 or 14 (4.05 mmol), in methanol (40 ml) at −78 °C,
until the solution turned blue. The resulting blue solution was purged with oxygen for 5 min,
and NaBH4 (1.53 g, 40.5 mmol) was added. After the mixture had been stirred at 0 °C for 4 h,
saturated aqueous NH4Cl was added. The reaction mixture was extracted with EtOAc,
washed with brine, dried with MgSO4, and then concentrated under reduced pressure,
followed by purification by silica gel chromatography affording primary alcohol 15 or 16.
4.4.1
Benzyl
(5R,6R)-5-(2-hydroxyethyl)-2,2,3,3,9,9,10,10-octamethyl-4,8-dioxa-3,9-
disilaundecan-6-ylcarbamate (15)
15 was obtained as a colorless oil; [α]2D5 +6.8 (c 0.8, CHCl3); IR (neat) νmax 2952, 2927, 2856,
1
2373, 2345, 2320, 1708, 1500, 1471, 1252, 1105, 836, 780, 757 cm−1; H NMR (400 MHz,
CDCl3) δ 7.31‒7.41 (m, 5H), 5.01‒5.19 (m, 3H), 4.17 (t, J = 5.9 Hz, 1H), 3.61‒3.78 (m, 4H),
13
3.52 (t, J = 8.8 Hz, 1H), 1.78 (q, J = 6.5 Hz, 2H), 0.89 (s, 18 H), 0.03‒0.19 (m, 12H); C
NMR (101 MHz, CDCl3) δ 156.5, 136.5, 128.5, 128.2, 67.8, 66.8, 61.5, 59.6, 55.2, 36.9, 25.9,
25.8, 18.1, 18.0, −4.5, −4.8, −5.4; HRMS (EI+) [(M)+] m/z calcd for C25H47NO5Si2 497.2993;
found 497.2991.
4.4.2 Benzyl benzyl[(5R,6R)-5-(2-hydroxyethyl)-2,2,3,3,9,9,10,10-octamethyl-4,8-dioxa-3,9-
disilaundecan-6-yl]carbamate (16)
16 was obtained as a colorless oil; [α]2D5 −8.8 (c 0.7, CHCl3); IR (neat) νmax 3735, 3725, 3705,
3680, 3632, 3623, 3599, 2926, 2855, 2360, 2341, 2293, 1704, 1689, 1461, 1252, 1219, 835,
773, 669 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.09‒7.40 (m, 10H), 5.01‒5.28 (m, 2H), 4.74‒
4.89 (m, 1H), 4.40‒4.52 (m, 1H), 4.17‒4.38 (m, 1H), 3.94‒4.15 (m, 1H), 3.59‒3.85 (m, 4H),
2.30‒2.46 (m, 1H), 1.69‒1.99 (m, 2H), 0.77‒0.91 (m, 18H), −0.16‒0.11 (m, 12H); 13C NMR
(101 MHz, CDCl3) δ 157.2, 139.3, 136.3, 128.3, 128.2, 127.9, 127.2, 126.7, 71.1, 67.3, 62.5,
59.4, 50.7, 36.4, 25.9, 25.8, 18.1, 17.9, −4.7, −4.9, −5.6; HRMS (EI+) [(M)+] m/z calcd for
C32H53NO5Si2 587.3462; found 587.3468.
8