An Effective Route for Formylation of Sensitive Aromatic Ring Systems: Syntheses and Photochemical Studies of the Synthesized Systems

Shaurya, Alok (2013) An Effective Route for Formylation of Sensitive Aromatic Ring Systems: Syntheses and Photochemical Studies of the Synthesized Systems. Masters thesis, Indian Institute of Science Education & Research Kolkata.

PDF (MS Dissertation of Alok Shaurya (08MS05)) ALOK_SHAURYA-08MS05-MSThesis.pdf - Submitted Version Restricted to Repository staff only Download (1MB)

Abstract

The photoopening kinetics has been shown to increase in all the analogues of DHP synthesized (marginal increase in Br-DHP-CHO). Also, compared to DHP, frormylation decreased the thermochomism too. Based on this we can isolated either isomers. Compared to BDHP, the photoopening kinetics has infact increased multiple time, especially Formyl BDHP which has photoopening rate constant about 8 times that of BDHP. However, there is only marginal improvement over UV reversal rate. Unlike benzo group, we cannot attribute the difference in rate caused due to formylation to increased conjugation and thus increased stability of CPD. The electron withdrawing abilities of CHO seems to be the plausible cause for the effect. It is well known that presence of electron withdrawing or donating groups on diene or dienophile affects kinetics of electrocyclization reaction (or for that matter any pericyclic reaction). Thus, we may conclude that fomyl group, because of its electron withdrawing effect onDHP reduces thermochromism can be used in synthesis of better switching DHP analogues.

Actions (login required)

View Item