CHEM01200604012 Dibakar Goswami - Homi Bhabha National ...

3 1.2 In (1.0) [bmim][Br] -- 6 78 11.0:42.0: 37.0
4. 4 Ga (2.5) H 2 O KI + LiCl,
16 NR --
sonication
5 3.5 Ga (2.5) THF KI + LiCl,
16 NR --
sonication
6 1.2 Ga (1.0) [bmim][Br] -- 7 79 3.4:44.5:52.1
7. 3.5 Bi (2.5) H 2 O KI + LiCl 20 65 7.2:31.8:61.0
8 3.0 Bi (2.0) THF KI + LiCl 12 43 12.0:22.0:66.0
9 1.5 Bi (1.2) [Bmim][Br] -- -- 72 5.0:35.4:59.6
a The reactions were carried out at 2 mmol scale. The yields refer to those of isolated pure
isomers. The isomeric ratios were determined from the isolated yields. NR: no reaction.
The reaction of 8 with 3 (Scheme 6, Table 7) using Bi in H 2 O, THF and
[bmim][Br]proceeded with modest diastereoselectivity, with the generation of anti-anti
isomer 9d as the major diastereoisomer in all the cases. All these reactions could be
accomplished much faster in [bmim][Br] with almost stoichiometric amounts of the
reagents. In other solvents, the results were significantly inferior, even with a large excess
of the reagents and prolonged reaction time.
Chapter IV: Asymmetric synthesis of some bio-active organic compounds
In this chapter, the syntheses of i) (R)-arundic acid (16), a novel neuroprotective
agent against Alzheimer disease; 9 ii) the octadienamide unit of the cryptophycins (22),
potent, tumor-selective tubulin binding antimitotic agents with excellent activity against
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