1
2
3
4
5
6
Experiment 7, page 6
Record the 1H nmr and IR spectra, m.pt. and optical rotation of your product. Details of the latter
procedure can be found in Harwood and Moody. Use a concentration of 1.0g/100 mL of
chloroform.
From the optical rotation, estimate the enantiomeric excess of your material, assuming a linear fit of
eeto rotation (not always a valid assumption - why not? Discuss in your report!)
Find a suitable solvent for recrystallisation of your diol, and perform the recrystallisation, drying
your crystals in air as before. Now re-measure you optical rotation at the exact same concentration
as you used before. Calculate the enantiomeric excess of your recrystallised material. Is there a
difference?
Write up
The write up should conform to a J. Chem. Soc., Perkin Trans. I, style (Title, Abstract,
Introduction, Results and Discussion, Experimental, References). Your introduction must include
discussion of the following points:
a)three recent (post-1993) synthetic applications of the asymmetric dihydroxylation reaction in
organic synthesis from the primary literature;
a)examples from the recent (post 1993) primary literature of three other types of catalytic
asymmetric reaction.
References and Notes
1."Asymmetric Synthetic Methodology", D. J. Ager and M. B. East, CRC,New York,
1996. Note that David Ager is an Imperial College graduate!
2."Catalytic Asymmetric Synthesis", ed. I. Ojima, VCH, Weinheim, 1993
3.For an excellent account of the discovery of the Sharpless AE reaction, see: C. H.
Behrens, K. B. Sharpless, Aldrichimica Acta, 1983, 16, 67; see also: R. A. Johnson, K.
B. Sharpless, in "Comprehensive Organic Synthesis", eds. B. M. Trost, I. Fleming,
Pergamon, New York, 1991, vol 7, p389
4.H. C. Kolb, M. S. van Nieuwenhze, K. B. Sharpless, Chem. Rev., 1994, 94, 2483.
Hartmuth Kolb obtained his Ph.D. from Imperial College in 1992!
5.G. G. Li, H. T. Chang, K. B. Sharpless, Angew. Chem. Int. Ed. Engl.,1996, 35, 451
6.M. J. Cleare, P. C. Hughes, W. P. Griffith, M. J. Wright, J. Chem. Soc., Dalton
Trans., 1977, 941
Steve Marsden, 28/9/98