Azidohydrins, preparation

Allylic fra i-l,2-azidohydrins prepared by Lewis-acid-catalysed ring opening of cyclic vinyl epoxides with sodium azide via an 5 2 mechanism have been found to isomerize to trans-l,4-azidohydrins via a suprafacial allyl azide [3,3]-sigmatropic rearrangement (Scheme 16). ... 

A further advantage of this protocol is that it allows the azidohydrin intermediate to be isolated. This will facilitate important mechanistic work to clarify the nature of the reactive species responsible for the ring expansion. Although only the preparation of azepin-2-... 

The preparation of 22 was accomplished by a sequence involving the sodium borohydride reduction of phenacyl azide, followed by the conversion of the resulting azidohydrin to the azidochloride, which was then subjected to base-catalysed elimination (equation 5). 

Vicinal azidohydrins have been prepared by treating epoxides with Et Al/NH in toluene.This mild and selective transformation of... 

Other oxidative double bond azidations have been reported. Thus an azidohydrin was formed from pregnenolone acetate and chromyl azide (NaNs, Chromium(VI) Oxide) and steroidal dienones reacted with TMSNs/Leadf/V) Acetate to give diazido compounds. Vicinal diazides also result from alkenes and Fe Manganese(IH) Acetate (eq 9), or lodosylbenzene and NaNs. Anti-Markovnikov selenoazido products were prepared from the reaction of azide ion with alkenes and (Diace-toxyiodo)benzene/Diphenyl Diselenide (eq 10) a-keto azides (with TMSN3) are formed without PhSeSePh. ... 

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