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5.5.2. Methyl 2,3-di-O-benzyl-5,6,7-trideoxy-7-(tri-n-
butyl)stannyl-hept-5-(Z)-eno-b- -ribo-furanoside (Z)-
10.9 Hz, CH2Ph), 4.65 (m, 5H, 3×CH2C6H5), 4.59 (d,
J1,2 0.8 Hz, H-1),, 3.85 (dd, J3,4 9.3 Hz, H-3), 3.83 (dd,
J4,5 9.0 Hz, H-4) 3.75 (dd, J2,3 2.3 Hz, H-2), 3.58 (dd,
J5,6 5.2, J5,7 1.9 Hz, H-5), 3.30 (s, OCH3), 2.54 (ddd, J6,7
9.2 Hz, H-6), 1.30 (m, CH2CH2CH2CH3), 0.88 (t, J 6.9
Hz, CH2CH2CH2CH3). 13C NMR (400 MHz) l: 138.5
(C-7), 2×138.9 and 138.5 (3×Cquat benzyl), 117.1 (C-8),
98.8 (C-1), 80.6, 76.1, 74.7, 74.0, (C-2,3,4,5), 74.7, 72.3,
71.9 (3×CH2Ph), 54.6 (OCH3), 44.2 (C-6), 31.8, 29.8,
22.7 (CH2CH2CH2CH3), 14.2, (CH2CH2CH2CH3).
HRMS m/z: 553.2919 [C34H42O5Na (M+Na+) requires
553.2924].
D
2616. H NMR (400 MHz) l: 5.80 (ddd, J5,6 9.1 Hz,
H-6), 5.07 (dd, J4,5 9.2 Hz, H-5), 4.92 (dd, J3,4 6.8 Hz,
H-4), 4.88 (d, J1,2 0.7 Hz, H-1), 4.69 and 4.64 (d, JA,B
12.2 Hz, CH2Ph), 4.54 and 4.53 (d, JA,B 12.0 Hz,
CH2Ph), 3.88 (dd, J2,3 4.7 Hz, H-3), 3.82 (dd, H-2), 3.32
(s, OCH3), 1.93 (ddd, J5,7a 1.1, J6,7a 10.2, J7a,7b 11.3 Hz,
H-7a), 1.80 (ddd, J5,7b 0.9, J6,7b 8.9 Hz, H-7b), 1.47 and
1.26 (m, SnCH2CH2CH2CH3), 0.89 (m, SnCH2CH2-
CH2CH3). 13C NMR (400 MHz) l: 138.1, 138.0 (2×
Cquat benzyl), 134.2, 123.7 (C-5,6), 106.0 (C-1), 82.9,
80.5, 76.7 (C-2,3,4), 2×72.3 (2×CH2Ph), 54.9 (OCH3),
29.1, 27.3 (SnCH2CH2CH2CH3), 13.7 (SnCH2CH2-
CH2CH3), 11.20 (C-7), 9.3 (SnCH2CH2CH2CH3).
1
5.4.5. Methyl 2,3,4-tri-O-benzyl-6,7,8-trideoxy-8-butyl-
oct-6-(E)-eno-a-D
-manno-1,5-pyranoside 12. 1H NMR
5.5.3. Methyl 2,3-di-O-benzyl-5,6,7-trideoxy-(5S)-(tri-n-
(200 MHz) l: 5.88 (ddd, J7,8a 6.6, J7,6 15.4 Hz, H-7),
5.58 (dd, J5,6 7.6 Hz, H-6), 4.70 (m, 3×CH2Ph), 4.63 (s,
H-1), 3.96 (dd, J4,5 9.0 Hz, H-5), 3.86 (dd, J3,4 9.3, J2,3
3.1 Hz, H-3), 3.77 (dd, J1,2 2.0 Hz, H-2), 3.71 (dd, H-4),
3.29 (s, OCH3), 2.08 (m, H-8a, H-8b), 1.25 (m,
CH2CH2CH2CH3), 0.87 (t, J 6.9 Hz, CH2CH2CH2-
CH3). 13C NMR (200 MHz) l: 138.6, 138.5, 138.3
(3×Cquat benzyl), 135.9 and 127.2 (C-6,7), 99.0 (C-1),
79.7 and 78.9 (C-3,4), 74.9, 73.1 (C-2,5), 75.0, 72.7, 72.3
(3×CH2Ph), 54.7 (OCH3), 32.4 (C-8), 31.5, 28.6, 22.5
(CH2CH2CH2CH3), 14.0 (CH2CH2CH2CH3). HRMS
m/z: 553.2930 [C34H42O5Na (M+Na+) requires
553.2924].
butyl)stannyl-hept-6-eno-b-
D
-ribo-furanoside
27.
1H
NMR (500 MHz) l: 5.88 (ddd, J6,7a 17.2, J6,7b 10.7 Hz,
H-6), 4.81 (s, H-1), 4.79 (dd, J5,7a 1.8 Hz, H-7a), 4.75
(dd, J5,7b=2.0 Hz, H-7b), 4.67 and 4.60 (d, JA,B 12.1
Hz, CH2Ph), 4.53 and 4.44 (d, JA,B 11.8 Hz, CH2Ph),
4.35 (dd, J3,4 8.0, J4,5 4.1 Hz, H-4), 3.89 (dd, J2,3 4.7 Hz,
H-3), 3.78 (d, H-2), 3.35 (s, OCH3), 2.43 (dd, J5,6 11.0
Hz, H-5), 1.47 and 1.29 (SnCH2CH2CH2CH3), 0.88
(SnCH2CH2CH2CH3). 13C NMR (500 MHz) l: 138.07
(C-6), 137.9, 137.8 (2×Cquat benzyl), 110.4 (C-7), 105.2
(C-1), 82.8 (C-4), 80.3 (C-2), 79.0 (C-3), 72.2, 72.1
(2×CH2Ph), 55.0 (OCH3), 35.7 (C-5), 29.1, 27.4
(SnCH2CH2CH2CH3), 13.7 (SnCH2CH2CH2CH3), 9.3
(SnCH2CH2CH2CH3).
HRMS
m/z:
667.2780
[C34H52O4SnNa (M+Na+) requires 667.2799].
5.5. Reaction of allyl furanosides with ‘Bu3SnCu’
In the NMR spectra of 27 obtained from (Z)-25 addi-
tional resonances at l 3.83 and 2.37 (1H) and 109.9,
105.8, and 55.7 (13C) ppm were observed. Although it
was not possible to establish precisely the structure of
the compound present in ca. 10% in the mixture, it was
assumed to be the alternative 5R isomer on the basis of
the decomposition experiment (see Section 5.6).
This reaction was performed under conditions
described in method b.
Reaction of mesylate (E)-25 with ‘Bu3SnCu’ provided
allyltins (E)-26 (primary, 47%), and 27 (secondary,
16%, single isomers) together with minute amounts of
butylated product 29 (5%, single isomer).
5.5.4.
Methyl
2,3-di-O-benzyl-5,6,7-trideoxy-7-C-
-ribo-furanoside (Z)-28. [h]D
Reaction of mesylate (Z)-25 with ‘Bu3SnCu’ provided
allyltins (Z)-26 (primary, 6%), and 27 (secondary, 19%,
contaminated with ca. 2% of the opposite isomer)
together with butylated products (Z)-28 (13%) and 29
(45%, ca. 1:1 mixture of stereoisomers).
(butyl)-hept-5-(Z)-eno-b-
D
1
−2.1 (c 1.0, CHCl3). H NMR (400 MHz) l: 5.71 (ddd,
J6,7a 6.9, J6,7b 7.2 Hz, H-6), 5.40 (ddd, J5,7 1.6 Hz, J5,6
11.0 Hz, H-5), 4.98 (ddd, J4,6 0.9, J4,5 8.4 Hz, H-4), 4.88
(s, H-1), 4.70 and 4.65 (d, JA,B 12.3 Hz, CH2Ph), 4.55
and 4.50 (d, JA,B 12.1 Hz, CH2Ph), 3.90 (dd, J3,4 7.3 Hz,
H-3), 3.84 (d, J2,3 4.6 Hz, H-2), 3.32 (s, OCH3), 1.75 (d,
H-7b), 1.74 (d, H-7a), 1.64, 1.36 and 1.31 (m,
CH2CH2CH2CH3), 0.92 (t, J 7.3 Hz, CH2CH2CH2-
CH3). 13C NMR (400 MHz) l: 137.9, 137.8 (2×Cquat
benzyl), 130.4, 128.9 (C-5,6), 106.1 (C-1), 82.6, 80.1,
76.5 (C-2,3,4), 72.4, 72.3 (2×CH2Ph), 54.9 (OCH3),
27.8, 26.8, 17.5 (CH2CH2CH2CH3), 13.6 (CH2CH2-
CH2CH3), 13.3 (C-7). HRMS m/z: 433.2389
[C26H34O4Na (M+Na+) requires 433.2349].
5.5.1. Methyl 2,3-di-O-benzyl-5,6,7-trideoxy-7-(tri-n-
butyl)stannyl-hept-5-(E)-eno-b-
D
-ribo-furanoside
(E)-
1
2616. H NMR (400 MHz) l: 5.92 (ddd, J5,6 15.0 Hz,
H-6), 5.21 (dd, J4,5 8.4 Hz, H-5), 4.86 (s, H-1), 4.65 and
4.56 (d, JA,B 12.0 Hz, CH2Ph), 4.59 and 4.51 (d, JA,B
12.1 Hz, CH2Ph), 4.51 (dd, J3,4 7.4 Hz, H-4), 3.84 (dd,
H-3), 3.81 (dd, J1,2 0.6, J2,3 4.5 Hz, H-2), 3.34 (s,
OCH3), 1.77 (dd, J5,7a 1.0, J6,7a 8.8 Hz, H-7a), 1.76 (dd,
J5,7b 0.9, J6,7b 8.4 Hz, H-7b), 1.46 and 1.28 (m,
SnCH2CH2CH2CH3), 0.87 (m, SnCH2CH2CH2CH3).
13C NMR (400 MHz) l: 138.0, 137.9 (2×Cquat benzyl),
135.2, 124.5 (C-5,6), 105.6 (C-1), 82.8, 82.4, 80.1 (C-
2,3,4), 72.5, 72.2 (2×CH2Ph), 54.9 (OCH3), 29.0, 27.3
(SnCH2CH2CH2CH3), 14.50 (C-7), 13.7 (SnCH2-
CH2CH2CH3), 9.1 (SnCH2CH2CH2CH3).
5.5.5.
(butyl)-hept-6-eno-b-
Methyl
2,3-di-O-benzyl-5,6,7-trideoxy-5-C-
D
-ribo-furanoside 29. One isomer
obtained in reaction of (E)-25: [h]D +19.7 (c 0.6,
1
CHCl3). H NMR (200 MHz) l: 5.59 (ddd, J6,7b 17.1
Hz, J6,7a 10.0 Hz, H-6), 5.40 (dd, J5,7a 1.8 Hz, H-7a),
4.88 (dd, J5,7b 2.2 Hz, H-7b), 4.84 (s, H-1), 4.68 and