Substituent Interactions in Di- and Tri-acyl Derivatives of cis- and trans- 2-Hydrazinocyclopentanol

Abstract

The action of thionyl chloride followed by an alkaline work-up quantitatively isomerizes trans-1,2-dibenzoyl-1-(2-h~droxylcyclopentyl)hydrazine (5) to cis-2-benzoyl-I-(2-benzoyloxycyclopentyl)hydrazine (3). One equivalent of tosyl chloride in pyridine converts 5 to an intermediate which can be hydrolyzed to a mixture of 3 and 5 or can be transformed to the N-tosyl derivative 13 by tosylation and then hydrolysis. Oxazolidine structures are s~~ggested as intermediates for these reactions.The alcohol 2 can also be isomerized to 3, using 0.8 N aqueous ethanolic hydrochloric acid, to which 5 is inert. The ester 3 is again the major product in the hydrolysis by this acid mixture of the cis-tribenzoyl derivative 17, the cis-N,-p-anisoyl derivative 21a and the cis-N,-acetyl derivative 216, the amide group being cleaved much more rapidly than the ester, especially in the case of 216. A mechanism involving ester participation by way of an oxazolidinium cation is proposed for these amide hydrolyses, and this is supported by tracer studies.The trntu-esters 24n and b hydrolyze mainly at the ester group with retention of configuration. Polynlorphism is a common phenomenon among thc title compounds.L'action du chlor~lre de thionyle suivie d'un traitement alcalin isoniCrise quantitativement le traiudibenzoyl-1,2 (hydroxyl-2 cyclopenty1)-l hydrazine (5) en cis benzoyl-2 (benzoyloxy-2 cyclopenty1)-l hydrazine (3). Un equivalent de chlorure de tosyle dans la pyridine transforme 5 en un intermediaire qui peut Ctre hydrolyse en un melange d e 3 et 5 ou convertit en derive N-tosyle 1 3 par tosylation puis hydrolyse. Les structures oxazolidines ont ete suggCrees comme intermediaires reactionnels. L'isomCrisation de I'alcool2 en 3 est Bgalement possible en presence d'une solution aqueuse Cthanolique d'acide chlorhydrique 0.8 N pour laquelle 5 est inerte. L'ester 3 reste encore le produit majoritaire dans I'hydrolyse par ce melange acide, du derive cir-tribenzoyle 17, du derive cis N,-p-anisoyle 21a et du dCriv6 cis-N,-acetyle 21b, le groupe amide etant dive beaucoup plus rapidenlent que I'ester specialement dans le cas de 21b. Un mecanisme avec participation de I'ester par un cation oxazolidinium a CtC propose pour les hydrolyses de ces amides; ce mecanisme a ete confirm6 par les Ctudes par traceur.Les esters tratrs 24a et 6 s'hydrolysent principalement sur le groupe ester avec retention de configuration. Le polymorphisme est un phenomene conimun parlni les composes de cette etude.[Traduit par le journal]Can. J . Chcn., 51. 1587 (1973) In earlier work (1) we used as partial proof of the structure of 1, the dihydro derivative of the thermal rearrangement product of cyclopentadiene and azodibenzoyl, its ready hydrolysis by acid to cis-1,2-dibenzoyl-1-(2-hydroxycyclopenty1)hydrazine (2). The alcohol 2 was not itself isolated, but'rather its isomer, the ester 3, and the further hydrolysis product 4. The intermediacy of 2 ~ was, however, de~i~onstrated by t.l.c., and it was confirmed that under the hydrolysis conditions (0.8 N hydrochlor...

Chemistry of Hydrazinoalcohols and their Heterocyclic Derivatives. Part 1. Synthesis of Hydrazinoalcohols

“…The thermolabile Diels-Alder adducts of azodibenzoyl and cyclopentadiene were applied for the synthesis of 2-hydrazinocyclopentanol derivatives [133,134].…”