Abstract:
Part-1: Conversion of (+)-R-limonene 1 into hetero Diels Alder dimer.
Part-2: Serendipitous discovery: Direct Conversion of 3 into (+)-cymbodiacetal 4 on silica gel column.
The domino reactions are initiated by 1O2 (singlet oxygen) and pass through the intermediates (not isolated) as follows:
P (unstable)---->Q (via rearrangement)---->R (enol a-epoxide) followed by acid catalysed rearrangement giving 4.
Highlights:
- Biosynthetic hypothesis led to a short and beautiful synthesis of (+)-cymbodiacetal 4.
- Single step serendipitous conversion of 3 in to 4 demonstrated amazingly simple biosynthetic route.
- The steps involved on silica gel column need further study for reproducibility.
Biography:
Prof. Dr. S.K. Paknikar After getting a PhD from University of Pune under the supervision of Professor S.C. Bhattacharyya, Prof. Dr. S.K. Paknikar worked as a Research Associate in Organic Chemistry with Professor R. B. Bates the University of Arizona, Tucson and a visiting scientist at Czechoslovak Academy of Sciences, Prague, started his teaching career at Indian Institute of Technology, Mumbai and moved to Goa in1970. A Senior DAAD fellow at Pharmaceutical Institute University of Bonn, Germany and a National fellow of the University Grants Commission (UGC) India, while working as a Head, Department of Chemistry, Prof. Dr. S.K. Paknikar is a well known and respected name in the field of Natural products and Organic Chemistry. On the 26th June 2024, he completed 89 and at this young age, he continues his pursuit of excellence in Chemistry – having been a successful Industry Consultant with a few key industrial organizations, National & International for over 30 years post retirement. With a research experience of about 69 years that includes a teaching experience of 28 years, Prof. Dr. S. K. Paknikar has been a guide to 16 PhD students and published over 150+ research articles in peer reviewed National and International journals. He was a consultant with Merck, India (Goa) for 20+ years, with VERGO Pharma (Goa) for 7 Years & Siddharth Chemicals (Goa) for 25+ Years. Since 2022, he serves as the Honorary Research Advisor at Nishant Aromas, Palghar, India.
