ISOLATION & FIRST TOTAL ASYMMETRIC SYNTHESIS OF NEW PHENOLIC CONSTITUENTS: ISOLATION FROM WALSURA TRIFOLIATA
L. V. Ramana, K. M. Ch. Apparao*, B. Nageswara Rao and M. Suri Appa Rao
ABSTRACT
Previously we have isolated & synthesized the (2R, 3R) flavanol[3,4] and now continued the research on another one new Phenylpropanoid unit containing (2R, 3S) flavanol is abundant molecule in plant source, have been isolated from the leaves of Walsura trifoliata. The structure were conformed on the basis of spectroscopic evidence mainly 2D-NMR, HRESIMS and unambiguously confirmed by alternative syntheses. The synthesis of this natural product, is good yield from inexpensive and readily available starting materials of Phloroglucinol dihydrate exemplifies the powerful synthetic utility afforded by the Grubbs-2 RCM catalyst reaction, Wittig reaction and sharpless dihydroxylation using AD-mix -α. The important impact of the Wittig reaction on modern synthetic organic chemistry was recognized by the 1979 Nobel Prize that was awarded in part to Georg Wittig for his discovery and subsequent development of this reaction.
Keywords: 3S-Flavan 3-ols, Phenylpropanoid synthesis, Phloroglucinol dehydrate.
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