O-acyl derivatives of cyclopentanone and cycloheptanone oximes

Abstract

By acylation of cyclopentanone and cycloheptanone oximes with carboxylic acids anhydrides or chlorides new esters were obtained of cyclopentanone and cycloheptanone oximes and their spectral characteristics were investigated.Oximes of some aldehydes and ketones can serve as convenient and available synthons for preparation of fragrant substances and perfumes, and also of biologically active compounds. We formerly reported on the synthesis of oxime esters of vanillin and vanillal [1], menthone [2], D,L-, D-(+) and L-(-)-camphor [3], jasmorange [4], citral and veratraldehyde [5,6], cyclo-hexanone [7]. It was established that just the presence of methyl, dimethyl, and isopropyl groups in the molecules of fragrant substances obtained from oximes of menthone , camphor, jasmorange, citral, and veratraldehyde ensured the interaction with the olfactory and taste receptors and led to the feeling of odor or taste [2][3][4][5][6]. The oxime esters of cyclohexanone analogous to oxime esters of menthone [2] did not exhibit promising perfume or taste [7].The aim of this study consisted in the preparation of a series of new esters of cyclopentanone and cycloheptanone oximes (IIa and IIb). Cyclopentanone oxime esters IIIa-IIIq and cycloheptanone oxime esters IVaIVq were synthesized from cyclopentanone and cycloheptanone oximes (IIa and IIb) by treating with alkylcarboxylic acids anhydrides in the presence of catalytic quantity of perchloric acid (esters IIIa-IIId, IVa-IVd), or by chlorides of alkyl-, cycloalkyl-, and arylcarboxylic acids in the presence of pyridine (esters IIIe-IIIq, IVe-IVq) (Scheme 1). Yields of cyclopentanone and cycloheptanone oxime esters IIIaIIIq and IVa-IVq attained 80-91%.The composition and structure of obtained compounds IIIa-IIIq and IVa-IVq were confirmed by elemental analysis, IR, UV, 1 H NMR spectroscopy, cryoscopic measurements of molecular weight. According to 1 H spectroscopy the purity of compounds obtained was 94 ± 1%. The results of analysis and of the measurements of molecular weight of compounds synthesized are consistent with the calculated data. The attempts to Scheme 1. (CH 2 ) n O Ia, Ib (CH 2 ) n NOH IIa, IIb (CH 2 ) n NOC(O)R IIIa _ IIIq, IVa _ IVq (RCO) 2 O or RCOCl NH 2 OH

Sequential [3,3]-Sigmatropic Rearrangement/Nucleophilic Aryl­ation of N-(Benzoyloxy)enamides towards the Preparation of Cyclic β-Aryl-β-amino Alcohols

“…Prepared according to the general procedure using cyclopentanone oxime 26 (1.98 g, 20 mmol) to give 1c as a pale yellow oil; yield: 2.3 g (39%, 2 steps). IR (neat): 1782, 1724 cm -1 .…”