N. Maezaki et al. / Tetrahedron: Asymmetry 9 (1998) 179–182
181
Scheme 2.
4. For synthesis of racemic allosamizoline, (a) Goering, B. K.; Ganem, B. Tetrahedron Lett. 1994, 35, 6997–7000; (b) Trost, B.
M.; Vranken, D. L. V. J. Am. Chem. Soc. 1993, 115, 444–458; (c) Trost, B. M.; Vranken, D. L. V. J. Am. Chem. Soc. 1990,
112, 1261–1263. For synthesis of (−)-allosamizoline from sugar: (d) Blattner, R.; Furneaux, R. H.; Kemmitt, T.; Tyler, P.
C.; Ferrier, R. J.; Tiden, A.-K. J. Chem. Soc., Perkin Trans. 1 1994, 3411–3421; (e) Kitahara, T.; Suzuki, N.; Koseki, K.;
Mori, K. Biosci. Biotech. Biochem. 1993, 57, 1906–1909; (f) Simpkins, N. S.; Stokes, S.; Whittle, A. J. J. Chem. Soc.,
Perkin Trans. 1 1992, 2471–2477; (g) Simpkins, N. S.; Stokes, S.; Whittle, A. J. Tetrahedron Lett. 1992, 33, 793–796; (h)
Nakata, M.; Akazawa S.; Kitamura, S.; Tatsuta, K. Tetrahedron Lett. 1991, 32, 5363–5366; (i) Takahishi, S.; Terayama, H.;
Kuzuhara, H. Tetrahedron Lett. 1991, 38, 5123–5126. For synthesis of (−)-allosamizoline via enzymatic desymmetrization:
(j) Shrader, W. D.; Imperiali, B. Tetrahedron Lett. 1996, 37, 599–602; (k) Griffith, D. A.; Danishefsky, S. J.; Samuel, J. J.
Am. Chem. Soc. 1996, 118, 9526–8538; (l) Griffith, D. A.; Danishefsky, S. J. J. Am. Chem. Soc. 1991, 113, 5863–5864.
5. Maezaki, N.; Sakamoto, A.; Soejima, M.; Sakamoto, I.; Li, Y.-X.; Tanaka, T.; Ohishi, H.; Sakaguchi, K.; Iwata, C.
Tetrahedron: Asymmetry 1996, 7, 2787–2790 and references cited therein.
6. Madhavan, G. V. B.; Martin, J. C. J. Org. Chem. 1986, 51, 1287–1293.
7. The stereochemistry of the diastereomeric isomers was determined by examining the nuclear Overhauser effect (NOE).
By irradiating the α-methine proton of the benzyloxymethyl group, NOE was registered on the α-methine protons of the
hydroxy groups in the major product and the hydroxy protons in the minor products, respectively.
8. The reaction should be carried out at 4°C in the shortest possible time. Partial racemization of sulfurs was observed at higher
temperature and with longer reaction times.
9. The diastereomeric excess of 9 was determined by 1H-NMR spectroscopy.
10. The chiral auxiliary was recovered without decreasing the enantiomeric excess.
11. Dale, J. A.; Mosher, H. S. J. Am. Chem. Soc. 1973, 95, 512–519; Dale, J. A.; Mosher, H. S. J. Org. Chem. 1969, 34,
2543–2549. The chemical shifts due to the C2 and C5 methine protons of the (R)-(+)-MTPA ester of 10 are 4.27 ppm
and 3.73 ppm, respectively. The corresponding protons of the (S)-(−)-MTPA ester of 10 are 4.19 ppm and 3.85 ppm,
respectively.
12. Lin, C.-C.; Weitz-Schmidt, G.; Wong, C.-H. J. Am. Chem. Soc. 1996, 118, 6826–6840. Debenzylation using 10% Pd–C for
5 days gave the complex mixture.