Bestmann-Ohira Reagent: A Versatile Reagent in Organic Synthesis

Introduction

Bestmann-Ohira reagent [(1-diazo-2-oxopropyl)phosphonate] can be prepared by the reaction of dimethyl-2-oxopropylphosphonate, TosN₃ [¹a] or p-acetamidobenzenesulfonyl azide, [¹b] NaH, t-BuOK or Et₃N in benzene and THF. An alternative is the preparation using polymer-supported sulfonyl azide and t-BuOK in methylenchloride. [¹c] The Bestmann-Ohiro reagent is widely used in the conversion of primary alcohols, aldehydes, ketones, and amides into alkynes. Recently, it was employed in the synthesis of pyrazoles as well as 1,3-oxazoles.

Scheme 1

References

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