Small and Smart: Adventures in Epihalohydrin Chemistry

Abstract

The present personalized account aims to highlight reactions of epichlorohydrin and epibromohydrin with free and masked dianions. These reactions permit convenient syntheses of a variety of products, such as 2-(alkylidene)tetrahydrofurans (which can be further functionalized by hydrogenation or ring-transformation reactions), cyclopropanes, γ-butyrolactams, oxazines, oxazolo[3,4-b]pyridazin-7-ones, or 2-(alkylidene)thiazolidines. In general, the reactions proceed with very good regioselectivity.

1 Introduction

2 Reactions of Masked Dianions

2.1 Synthesis of 2-(Alkylidene)tetrahydrofurans

2.2 Functionalization of 2-(Alkylidene)tetrahydrofurans

3 Reactions of Free Dianions

3.1 Synthesis of 2-(Alkylidene)tetrahydrofurans

3.2 Functionalization of 2-(Alkylidene)tetrahydrofurans

3.3 Synthesis of γ-Butyrolactams

3.4 Synthesis of 5,6-Dihydro-4H-1,2-oxazines

3.5 Synthesis of Oxazolo[3,4-b]pyridazin-7-ones

3.6 Synthesis of Cyclopropanes

3.7 Synthesis of 2-(Alkylidene)thiazolidines

4 Conclusions

Key words

cyclizations - dianions - epoxides - regioselectivity - silyl enol ethers - epihalohydrins

Publication History

Received: 22 February 2023

Accepted after revision: 09 March 2023

Article published online:
05 April 2023

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