• Dr. R.K.Pandey
• Dr.L.K. Sahay

Interaction of homophthalic acid (I) with acetic anhydride in the presence of dry pyridine at room temperature furnished 4-acetylisochroman-1, 3-dione (II). This isochromandione was converted quantitatively on treatment with 80% H2SO4 into 4-carboxy-3-methylisocoumarin (III) getting partly decarboxylated during the reaction to 3-methylisocoumarin (IV) depending on the temperature of the reaction. The present work embodied in the dissertation of focuses on the new synthesis of 3, 4-dihydroxy-3-methylisocoumarin (V) and Pinacol-Pinacolone rearrangement of (V) by heating with KBrO3/H2SO4 (dil) yielded the 3-methylisocoumarin-1, 4-dione (VI) Attempted epimerisation of 3, 4-dihydroxy-3-methylisocoumarin (V) in aqueous NaOH solution, the reaction mixture was acidifiled with concentrated hydrochloric acid and extracted with ether. The stereochemistry involved with a view to establish the conformation of the 3, 4-diol as also the pinacol-pinacolone rearrangement on it.

Dihydroxyisocoumarin, synthesis, conformation, pinacol-pinacolone rearrangement.

"Synthesis of 3,4-dihydroxy-3-methylisocoumarin and Pinacol-Pinacolone rarrangement on it", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 6, page no.638-643, June 2019, Available :http://www.jetir.org/papers/JETIR1906L93.pdf

"Synthesis of 3,4-dihydroxy-3-methylisocoumarin and Pinacol-Pinacolone rarrangement on it", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 6, page no. pp638-643, June 2019, Available at : http://www.jetir.org/papers/JETIR1906L93.pdf