用于从假紫罗兰酮合成 β-紫罗兰酮的新型环化剂,Pharmaceutical Chemistry Journal

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用于从假紫罗兰酮合成 β-紫罗兰酮的新型环化剂
Pharmaceutical Chemistry Journal ( IF 0.8 ) Pub Date : 1998-11-01 , DOI: 10.1007/bf02465835
Yu. D. Markovich , A. V. Panfilov , Yu. N. Platunov , A. A. Zhirov , S. I. Kosenko , A. T. Kirsanov

I$-紫罗兰酮-许多类胡萝卜素合成中的关键试剂，也广泛用于芳香化合物的化学中，通常通过假紫罗兰酮在各种环化剂的帮助下环化合成[1-15]。环化反应导致形成两种异构体的混合物，~z 和 13-紫罗兰酮。c-异构体和13-异构体之间的比例取决于反应条件并且可以在很宽的范围内变化。[3-紫罗兰酮的最大产率是通过使用大量过量的硫酸（每摩尔假紫罗兰酮超过 6 摩尔酸）作为环化剂来提供的。该方法用于13-紫罗兰酮的商业化生产，存在大量废硫酸不能重复参与工艺流程的问题。与此相关，为假紫罗兰酮环化为 13-紫罗兰酮的过程寻找新试剂是一项重要任务。这项工作的目的是研究使用三氟乙酸和硫酸或三氟乙酸和氟磺酸的混合物作为环化剂的可能性，以期减少或消除在从假紫罗兰酮生产 13-紫罗兰酮的过程中使用硫酸。根据薄层色谱 (TLC) 数据，假紫罗兰酮与三氟乙酸相互作用导致形成 cc-紫罗兰酮，然后在硫酸（或氟磺酸）的作用下异构化为 fl-紫罗兰酮。环化根据以下方案进行。该过程中的主要事件是导致假紫罗兰酮烯醇化的羰基质子化。这导致 C(9)-C(10) 双键的形成和 C(6)-C(7) 和 C(8)-C(9) 双键重排为 C(5) C (6) 和 C(7)-C(8) 位置，分别。在 C(2) 原子上形成的碳正离子通过新的 C(2)-C(7) 键稳定。在硫酸（或氟磺酸）的作用下，这种碳正离子在 C(5) C(6) 键上的后续发展导致形成能量上更有利的双键 C(6)C(7)。

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New cyclization agents for the synthesis of beta-ionone from pseudoionone

I$-Ionone-a key reagent in the syntheses of many carotenoids, also widely used in the chemistry of aroma compoundsis usually synthesized by cyclization of pseudoionone with the aid of various cyclization agents [1 15]. The cyclization reaction leads to the formation of a mixture of two isomers, ~zand 13-ionone. The ratio between c~and 13-isomer depends on the reaction conditions and may vary within broad limits. The maximum yield of [3-ionone is provided by using a large excess of sulfuric acid (above 6mole acid per mole pseudoionone) as the cyclization agent. This method, used in the commercial production of 13-ionone, poses the problem of utilization of a large amount of used sulfuric acid that cannot be repeatedly involved in the technological process. In connection with this, there is the important task of finding new reagents for the process of pseudoionone cyclization to 13-ionone. The purpose of this work was to study the possibility of employing the mixtures of trifluoroacetic and sulfuric or trifluoroacetic and fluorosulfonic acids as cyclization agents, with a view to reduce or eliminate the use of sulfuric in the 13-ionone production from pseudoionone. According to thin-layer chromatography (TLC) data, the interaction ofpseudoionone with trifluoroacetic acid leads to the formation cc-ionone, followed by its isomerization to fl-ionone under the action of sulfuric (or fluorosulfonic) acid. The cyclization proceeds according to the following scheme. The primary event in this process is carbonyl group protonation resulting in the enolization of pseudoionone. Thisleads to the formation of a C(9)-C(10) double bond and a rearrangement of the C(6)-C(7) and C(8)-C(9) double bonds to the C(5) C(6) and C(7)-C(8) positions, respectively. The carbocation formed at the C(2) atom is stabilized by the new bond C(2)-C(7). The subsequent development of this carbocation at the C(5) C(6) bond under the action of sulfuric (or fluorosulfonic) acid leads to the formation of an energetically more favorable double bond C(6)C(7).

更新日期：1998-11-01

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