Sama Ajay

‘Chiron’ approach to the total synthesis of macrolide (+)-Aspicilin

An efficient total synthesis of 18 membered macrolactone, (+)-Aspicilin (lichen macrolide) has been achieved in 12 linear steps with 10.2% overall yield from carbohydrate based building block D-glucal. Highlights of the strategy include preparation of 2-deoxysugar from protected glycal 14, two-carbon Wittig olefination of the Swern oxidised intermediate 7, union of ‘carbohydrate based’ fragment 5 and a long chain (C-11) chiral alcohol 6 by Yamaguchi esterification and finally ring closing metathesis of the resulting compound 4.

New Xanthone from the roots of Swertia cordata (G. Don) Clarke

Abstract The chloroform extract of Swertia cordata (G. Don) roots was subjected to column chromatography, afforded two (one new and one known) xanthones. Both the compounds were isolated for the first time from S. cordata. The structures of the isolated compounds were established on the basis of melting point,1D (1H NMR & 13C NMR) and 2D (1H 1H COSY, HSQC & HMBC) NMR spectroscopy, in addition to high-resolution mass spectrometry.