Synthesis 2015; 47(10): 1510-1518
DOI: 10.1055/s-0034-1380001
paper
© Georg Thieme Verlag Stuttgart · New York

Iodine-Mediated Annulation of S-Allylated α-Enolic Dithioesters: Rapid Access to 2-Alkylidene-1,3-dithiolanes at Room Temperature

B. Janaki Ramulu
Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi-221005, India   Email: mssinghbhu@yahoo.co.in
,
Sushobhan Chowdhury
Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi-221005, India   Email: mssinghbhu@yahoo.co.in
,
Anugula Nagaraju
Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi-221005, India   Email: mssinghbhu@yahoo.co.in
,
Suvajit Koley
Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi-221005, India   Email: mssinghbhu@yahoo.co.in
,
Namrata Anand
Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi-221005, India   Email: mssinghbhu@yahoo.co.in
,
Maya Shankar Singh*
Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi-221005, India   Email: mssinghbhu@yahoo.co.in
› Author Affiliations
Further Information

Publication History

Received: 02 December 2014

Accepted after revision: 12 January 2015

Publication Date:
27 February 2015 (online)


This paper is dedicated to Prof. Ganesh Pandey on the occasion of his 60th birthday

Abstract

A new and operationally and user-simple domino protocol for the efficient synthesis of 2-alkylidene-1,3-dithiolanes has been developed via molecular iodine mediated iodocyclization of S-allylated α-enolic dithioesters at room temperature. The attractive features of this strategy include mild reaction conditions, short reaction time (5 min), high atom economy, high selectivity, easy purification, excellent yields, and wide substrate scope. Notably, many examples gave the exocyclic double bond of the 1,3-dithiolane with Z-configuration, while others gave E/Z mixtures; interconversion of the E- and Z-isomers was observed under acidic and thermal conditions.

Supporting Information