4250
S. F. Barker et al. / Tetrahedron Letters 42 (2001) 4247–4250
15. Johnson, S. W.; Angus, D.; Taillefumier, C.; Jones, J. H.;
Watkin, D. J.; Floyd, E.; Buchanan, J. G.; Fleet, G. W.
J. Tetrahedron: Asymmetry 2000, 11, 4113–4125.
16. All specific rotations were measured in chloroform except
where otherwise stated. All new compounds in this paper
have satisfactory CHN microanalytical and/or HRMS
data.
8.3 Hz, H-4), 4.67 (d, 1H, Jgem 11.0 Hz, CHPh), 4.73 (dd,
1H, J2.3 5.6, J3.4 6.8 Hz, H-3), 4.85 (d, 1H, J2,3 5.6 Hz,
H-2), 7.28–7.40 (m, 5H, PhH); lC (CDCl3, 50.3 MHz):
15.3 (C-6), 53.2 (CO2CH3), 59.7 (C-3), 71.5 (CH2Ph),
73.7 (C-5), 81.5 (C-2), 85.2 (C-4), 128.3, 128.6, 128.9 (5C,
Ph), 138.4 (Cipso), 170.7 (C-1); m/z (APCI+) 265 (17%),
264 (M+H+−N2, 100), 220 (17), 158 (80).
17. Silylated cis-b-azidoester 18, oil; [h]2D2 −69.5 (c, 0.8); wmax
(thin film) 2111 (N3), 1761 (CꢀO) cm−1; lH (CDCl3, 200
MHz): 0.12 (s, 6H, Si(CH3)2), 0.97 (s, 9H, SiC(CH3)3),
1.13 (d, 3H, J6,5 6.5 Hz, H-6), 3.85 (s, 3H, CO2CH3), 3.97
(qd, 1H, J5,6 6.5, J5,4 2.7, Hz, H-5), 4.46 (ddd, 1H, J4,3
5.1, J4,5 2.7, J4,2 0.4 Hz, H-4), 4.82 (dd, 1H, J3,2 7.8, J3,4
5.1 Hz, H-3), 5.03 (d, 1H, J2,3 7.8 Hz, H-2); lC (CDCl3,
100.6 MHz): −3.9 (Si(CH3)2), 18.0 (C-6, SiC(CH3)3), 25.7
(SiC(CH3)3), 52.2 (CO2CH3), 55.3 (C-3), 67.3 (C-5), 79.1
(C-4), 90.3 (C-2), 169.6 (C-1).
18. (a) Sagakami, M.; Hamana, H. Tetrahedron Lett. 2000,
41, 5541–5547; (b) DeNinno, M. P.; Etienne, J. B.;
Duplantier, K. C. L. Tetrahedron Lett. 1995, 36, 669–672.
19. Benzyl cis-b-azidoester 17, oil; [h]2D2 −106.3 (c, 1.4); wmax
(thin film) 2116 (N3), 1760 (CꢀO) cm−1; lH (CDCl3, 400
MHz): 1.14 (d, 3H, J5,6 6.6 Hz, H-6), 3.80 (dq, 1H, J5,6
6.6, J4,5 3.7 Hz, H-5), 3.87 (s, 3H, CO2CH3), 4.59 (ddd,
1H, J2,4 0.6, J3,4 5.4, J4.5 3.7 Hz, H-4), 4.68 (d, 1H, Jgem
11.5 Hz, CHPh), 4.72 (d, 1H, Jgem 11.5 Hz, CHPh), 4.84
(dd, 1H, J2.3 7.3, J3.4 5.4 Hz, H-3), 5.14 (br d, 1H, J2,3
7.3, H-2), 7.27–7.38 (m, 5H, PhH); lC (CDCl3, 100.6
MHz): 14.8 (C-6), 52.3 (CO2CH3), 56.2 (C-3), 72.2
(CH2Ph), 73.6 (C-5), 79.2 (C-2), 92.3 (C-4), 127.6, 127.7,
127.8, 128.4 (5C, Ph), 138.3 (Cipso), 169.5 (C-1); m/z
(APCI+) 264 (M+H+−N2, 95%), 206 (90), 157 (50), 121
(100).
22. For a procedure for the bromine oxidation, see: Sun, R.
C.; Okabe, M. Org. Syn. 1993, 72, 48–53.
23. Wang, Y.; Fleet, G. W. J.; Storer, R.; Myers, P. L.;
Wallis, C. J.; Doherty, O.; Watkin, D. J.; Vogt, K.;
Witty, D. R.; Wilson, F. X.; Peach, J. M. Tetrahedron:
Asymmetry 1990, 1, 527–531.
24. Benzyl cis-b-azidoester 26, oil; [h]2D5 +128.8 (c, 1.05); wmax
(thin film) 2116 (N3), 1756 (CꢀO) cm−1; lH (CDCl3, 400
MHz): 3.67 (dd, 1H, Jgem 11.9, J4,5 2.9 Hz, H-5), 3.72 (dd,
1H, Jgem 11.9, J4,5% 3.0 Hz, H-5%), 3.89 (s, 3H, CO2CH3),
4.61 (d, 1H, Jgem 12.1 Hz, CHPh), 4.69 (d, 1H, Jgem 12.1
Hz, CHPh), 4.79–4.81 (m, 1H, H-4), 4.93 (dd, 1H, J2,3
7.6, J3,4 5.6 Hz, H-3), 5.22 (d, 1H, J2,3 7.6 Hz, H-2),
7.29–7.41 (m, 5H, PhH); lC (CDCl3, 100.6 MHz): 52.3
(CO2CH3), 56.7 (C-3), 69.4 (C-5), 73.8 (CH2Ph), 79.4
(C-2), 86.2 (C-4), 127.7, 127.9, 128.5 (5C, Ph), 137.6
(Cipso), 169.4 (C-1); m/z (APCI+) 295 (M+NH4+, 35%),
250 (M+H+−N2, 100%).
25. Benzyl trans-b-azidoester 23, oil; [h]2D6 +44.1 (c, 0.95);
wmax (thin film) 2112 (N3), 1760 (CꢀO) cm−1; lH (CDCl3,
400 MHz): 3.78 (dd, 1H, Jgem 10.8, J4,5 5.1 Hz, H-5), 3.85
(s, 3H, CO2CH3), 3.91 (dd, 1H, Jgem 10.8, J4,5% 6.0, H-5%),
4.62 (s, 2H, CH2Ph), 4.71–4.74 (m, 1H, H-3), 4.96–5.01
(m, 2H, H-2, H-4), 7.30–7.45 (m, 5H, PhH); lC (CDCl3,
100.6 MHz): 52.6 (CO2CH3), 58.8 (C-3), 68.6 (C-5), 73.7
(CH2Ph), 81.6 (C-2), 81.8 (C-4), 127.8, 128.4 (5C, Ph),
137.6 (Cipso), 170.0 (C-1); m/z (APCI+) 250 (M+H+−N2,
75%), 144 (100%).
20. The atomic coordinates for methyl 2,4-anhydro-6-deoxy-
5-O-benzyl-L-altronate 14 are available on request from
the Cambridge Crystallographic Data Centre, University
Chemical Laboratory, Lensfield Road, Cambridge CB2
1EW; the crystallographic numbering system differs from
that used elsewhere in the text. Any request should be
accompanied by the full literature citation for this paper.
21. Benzyl trans-b-azidoester 16, oil; [h]2D2 −30.0 (c, 1.0); wmax
(thin film) 2117 (N3), 1758 (CꢀO) cm−1; lH (CDCl3, 500
MHz): 1.28 (d, 3H, J5,6 5.8 Hz, H-6), 3.85 (s, 3H,
CO2CH3), 4.10 (dq, 1H, J5,6 5.8, J4,5 8.3 Hz, H-5), 4.56
(d, 1H, Jgem 10.9 Hz, CHPh), 4.61 (dd, 1H, J3,4 6.8, J4.5
26. For a description of the procedures used see: (a) Hunger-
ford, N. L.; Claridge, T. D. W.; Watterson, M. P.; Aplin,
R. T.; Moreno, A.; Fleet, G. W. J. J. Chem. Soc., Perkin
Trans. 1 2000, 3666–3679; (b) Brittain, D. E. A.; Watter-
son, M. P.; Claridge, T. D. W.; Smith, M. D.; Fleet, G.
W. J. J. Chem. Soc., Perkin Trans. 1 2000, 3655–3665,
and references cited therein.
27. Claridge, T. D. W.; Goodman, J. M.; Moreno, A.;
Angus, D.; Barker, S. F.; Taillefumier, C.; Watterson, M.
P.; Fleet, G. W. J. Tetrahedron Lett. 2001, 42, 4251–4255.
.