Page 146 - 2015-16

CSIR-IHBT Annual Report 2015-16

experiment between quinoline and the deuterated analogue d7- quinoline revealed a kinetic
isotope effect of kH/kD ≈ 1.50, indicating that the cleavage of C-H bond of quinoline N-oxide may or
may not be involved in the rate-limiting step. On the basis of these preliminary mechanistic
experiments and literature, a probable mechanistic pathway is depicted. Reaction might involve
1,3-dipolar cycloaddition followed by cleavage of N-O bond to provide the final product.

Mechanistic study and proposed reaction pathway
Quinoline substituted α–hydroxy carboxylic acid derivatives (3a) can be converted into
corresponding C-2 olefinated quinoline by simply heating at 100 0C for 24h without using any
additive or solvent albeit in low yield.

Metal free direct olefination
Phytochemistry:
Clematis graveolens: A new hederagenin based triterpenoid saponin, clematograveolenoside A
(1), along with three known
saponins, tomentoside A (2),
huzhangoside D (3) and
clematoside S (4), were isolated
from the roots of Clematis
graveolens. The structure of new
compound was elucidated as 3-O-
β-D-ribopyranosyl-(1→3)-α-L-
rhamnopyranosyl-(1→2)-[β-D-
g l u c o p y r a n o s y l - ( 1 → 4 ) - β - D - Structure of compounds isolated from clematis graveolens

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