Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1995-07-19
1997-09-02
Haley, Jacqueline
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
546144, 546147, 546174, 560170, 560177, 560186, 562567, C07D21514
Patent
active
056633483
DESCRIPTION:
BRIEF SUMMARY
This is a National Stage application of PCT/JP94/00056 filed Jan. 17, 1994 and published as WO94/17079 on Aug. 4, 1994.
1. TECHNICAL FIELD
The present invention relates to a novel optically active .beta.-aminoalkoxyborane complex and a process for producing an optically active alcohol, wherein the complex is applied as a reducing agent to a carbonyl compound. Particularly, it relates to a process for producing an optically active 1,3-syn-diol compound wherein this borane complex is applied to a 1,3-dicarbonyl compound.
2. BACKGROUND ART
Many physiologically active substances for pharmaceuticals, agricultural chemicals or cosmetics have a 1,2- or 1,3-syn-diol structure. For example, a series of HMG-CoA reductase inhibitors as one type of antihyperlipemia agents have a 1,3-syn-diol as a common partial structure at their mevalonic acid chain moieties, which constitutes an essential structure for developing the reductase inhibitory activities.
Further, among natural physiologically active substances, there are many substances which have a 1,3-syn-diol structure. For example, prostaglandin F1.alpha. and F2.alpha. having oxytocic activities or vasopressor activities, pentamycine which is a polyene macrolide antibiotic, amphotericine B which is a polyene-type antimycotic, misaquinolide A which is an antitumor macrolide, G-strophatine which is a cardiac glycoside and pulkerine which is a sesquiterpene contained in an Indian blanket (Gaillardia pulchella) may be mentioned.
Heretofore, various methods for preparing this 1,3-syn-diol have been developed by means of chemical techniques (Tetrahedron Lett., 28, 155 (1987), Tetrahedron Lett., 26, 2951 (1985)). However, these methods require many steps, since a first chiral center is introduced and a second chiral center is constructed based on the first chiral center, and it requires an extremely low temperature as a reaction condition to obtain the desired 1,3-syn-diol in high optical yield and at a high syn-selectivity. Thus, they had many industrial limitations.
Heretofore, a number of methods have been known for producing an optically active alcohol compound by asymmetrically reducing a carbonyl compound by means of an optically active reagent. Namely, many methods including, for example, a method by Corey et al. employing an optically active borane complex (E. J. Corey and A. V. Gavai, Tetrahedron Lett., 29, 3201 (1988)), a Meerwein-Ponndolf-Verley (MPV) type asymmetric reduction method (M. M. Midland, D. C. McDowell and Gabriel, J. Org. Chem., 54, 159 (1989)) and a method employing an enzyme or a microorganism (G. Frater, Helv. Chim. Acta, 62, 2815, 2829 (1979) may be mentioned.
For asymmetric reduction of aromatic carbonyl compounds, many reagents showing high selectivity have been developed. However, it has been considered difficult to attain high selectivity for asymmetric reduction of a dialkylcarbonyl even by using these reagents, and it has been possible to attain an asymmetric yield of only 50% ee at best. Generally, high-electrons of unsaturated groups of aromatic carbonyl compounds are considered to provide substantial effects in a transition state for asymmetric reduction, and for a dialkylcarbonyl with which no such substantial electronic effects can be expected, a reagent is required to have an ability of recognizing the difference in steric effects (Organic Synthetic Chemistry, Vol. 45, No. 2, p. 101 (1987)). Accordingly, in the case of a substrate such as 2-hexanone, no reducing reagent which is capable of sufficiently providing such an ability, has been known. The above-mentioned reagents for asymmetric reduction are all used for asymmetric reduction of monocarbonyl compounds only, and little applications to dicarbonyl compounds have been known.
On the other hand, a method by Yamazaki et al. employing an optically active borane complex is known (Japanese Unexamined Patent Publication No. 146786/1982). Namely, this method is directed to asymmetric reduction of acetophenones by means of an optically active borane complex prepared from (S)-1-benzyl-2-py
REFERENCES:
patent: 4897490 (1990-01-01), Sit et al.
Aust. J. Chem., vol. 22, pp. 427-429, 1969, B. Chauncy, et al., "A New Synthesis of Phenanthroindolizidine".
Aust. J. Chem., vol. 23, pp. 2503-2516, 1970, B. Chauncy, et al., "Synthesis of Phenanthroindolizidines".
Chemical Abstracts, vol. 70, Jul. 23, 1969, p. 368, AN-88024q.
Chemical Abstracts, vol. 74, Feb. 23, 1971, p. 326, AN-13313g.
Chemical Abstracts, vol. 107, Aug. 13, 1987, AN-39327q.
Chemical Abstracts, vol. 110, Feb. 17, 1989, AN-38872p.
Tetrahedron, vol. 14, 1961, pp. 284-287, T.R. Govindachari, et al., "Chemical Examination of Tylophora Asthmatica-IV".
Kashihara Hiroshi
Ohara Yoshio
Suzuki Mikio
Haley Jacqueline
Nissan Chemical Industries Ltd.
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