hydrazone from a,b conj aldehyde ?

[stratosphere]

im curious if a,b conjugation of cinnamaldehyde would interfere with hydrazone formation, if one were to attempt a wolff-kishner reduction of that material?

[Aurelius]

No.

https://www.thevespiary.org/rhodium/Rhodium/chemistry/cinnamaldehyde.html

[Rhodium]

I couldn't find any literature refs mentioning cinnamaldehyde hydrazone (the "hydrazine imine" of cinnamaldehyde) being converted to either propenylbenzene or allylbenzene.

Nevertheless, I found one where cinnamaldehyde tosylhydrazone (from para-toluenesulfonylhydrazine) is reduced to allylbenzene in 85% yield (bis(benzoyloxy)borane, NaOAc*3H₂O, CHCl₃, 1h, 0°C).

The reagent bis(benzoyloxy)borane is nothing to be afraid of, as it is easily made in situ from benzoic acid and BH₃.THF, the latter which in turn can be prepared by mixing equinormal amounts of NaBH₄ and H₂SO₄ in THF.



A mild and convenient conversion of ketones to the corresponding methylene derivatives via reduction of tosylhydrazones by bis(benzoyloxy)borane
George W. Kabalka, S. Timothy Summers

J. Org. Chem. 46, 1217-1218 (1981)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/carbonyl.deoxygenation.tsnhnh2-bh3-phcooh.pdf)

[GC_MS]

You seem to forget about ChemisTris' ?-asarone synthesis using 2,4,5-trimethoxycinnamaldehyde (which in turn has been prepared from ?-asarone) and TsNHNH₂:

Post 445839

(ChemisTris: "Conversion of B-asarone into [gamma] asarone", Chemistry Discourse)  

[stratosphere]

a perhaps naive question:
would the absesnce of literature references then indicate that wolff-kishner style reduction would not work in this case?

The reagent bis(benzoyloxy)borane is nothing to be afraid of

what about formation of the tosyl hydrazone?

i wonder about the aldehyde->dithioacetal followed by H2/Ni reduction route?

[Rhodium]

would the absesnce of literature references then indicate that wolff-kishner style reduction would not work in this case?

Yes, unfortunately, that is most often the case, at least when it comes to simple molecules like these.

I have however found some one-step deoxygenations of cinnamaldehyde to propenylbenzene/allylbenzene using cyanoborohydride with a lewis acid additive, which also seems to deoxygenate benzaldehydes to methylbenzenes and aralkyl ketones to hydrocarbons in high yield:


Chemoselective reductive deoxygenation of ,-unsaturated ketones and allyl alcohols
A. Srikrishna, R. Viswajanani, J. A. Sattigeri and C. V. Yelamaggad

Tetrahedron Letters 36(13), 2347-2350 (1995)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/cinnamaldehyde2propenylbenzene.pdf)
DOI:

10.1016/0040-4039(95)00252-8

Abstract
A simple and convenient procedure for a highly chemoselective reductive deoxygenation of ,-unsaturated ketones and allyl alcohols to olefins by sodium cyanoborohydride and boron trifluoride etherate in dry THF is described.



Reductive, selective deoxygenation of acylbenzofurans, aromatic aldehydes and ketones with NaBH₃CN-TMSCl
Vernon G. S. Box and Panayiotis C. Meleties

Tetrahedron Letters 39(39), 7059-7062 (1998)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/deoxygenation.nabh3cn-tmscl.pdf)
DOI:

10.1016/S0040-4039(98)01519-6

Abstract
Aromatic aldehydes, ketones and acylbenzo[b]furans have been reductively deoxygenated with sodium cyanoborohydride and the mild electrophile chlorotrimethylsilane.



A Simple and Convenient One Step Method for the Reductive Deoxygenation of Aryl Ketones to Hydrocarbons
Srikrishna, A.; Sattigeri, J. A.; Viswajanani, R.; Yelamaggad, C. V.

Synlett, (1) 93-94 (1995)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/deoxygenation.nabh3cn-bf3-et2o.pdf)