Stereocontrolled synthesis of D-pentitols, 2-amino-2-deoxy-D-pentitols and 2-deoxy-D-pentitols from D-glyceraldehyde acetonide

Minami, Norio; Ko, Soo S.; Kishi, Yoshito

doi:10.1021/ja00368a040

Cited by 228 publications

(37 citation statements)

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“…This distinctive selectivity was also observed in the similar types of reactions reported in Refs. [7] and [8]. In the same manner, reactions with the cis epoxy alcohol (3) and the epoxy alcohols (5) and (7) gave the corresponding hydroxy cyclic xanthates 4, 6, and 8 in 80, 81, and 77% yields, respectively, as shown in Scheme 3.…”

Section: Intvarnolecular Stereospecific Ring Opening Of a 23-epoxy Asupporting

confidence: 53%

“…The reactions were mediated by Lewis acids to form a cyclic carbonate in both cases. These reactions were effective for the stereospecific preparation of consecutive 1,2,3-triols and were used for polyol syntheses, particularly of sugars [7,8]. We attempted similar reactions in order to obtain a cyclic thiol carbonate from the corresponding acyclic thiocarbonate or thiourethane.…”

Section: Introductionsupporting

confidence: 46%

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Intramolecular ring opening of a 2,3‐epoxy alcohol by a xanthate anionic center; stereospecific preparation of 2‐mercapto‐1,3‐diol units

Uenishi

Motoyama

Nishiyama

et al. 1994

Heteroatom Chemistry

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Section: Intvarnolecular Stereospecific Ring Opening Of a 23-epoxy Asupporting

confidence: 53%

Section: Introductionsupporting

confidence: 46%

Intramolecular ring opening of a 2,3‐epoxy alcohol by a xanthate anionic center; stereospecific preparation of 2‐mercapto‐1,3‐diol units

Uenishi

Motoyama

Nishiyama

et al. 1994

Heteroatom Chemistry

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“…For example, the polyol substructure that appears in the oxopolyene macrolide (+)-roxaticin is available in nine steps from propane-1,3-diol upon three iterations of double carbonyl allylation [286]. Notably, high levels of catalyst-directed stereoselectivity are observed (For selected examples of catalyst directed diastereoselectivity, see: [289–296]). Analogous 1,3-polyol syntheses via iterative homologation in one direction also are reported [297].…”

Section: Iridium-catalyzed Transfer Hydrogenation For C–c Bond Formmentioning

confidence: 99%

Formation of C–C Bonds via Iridium-Catalyzed Hydrogenation and Transfer Hydrogenation

2010

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The formation of C-C bonds via catalytic hydrogenation and transfer hydrogenation enables carbonyl and imine addition in the absence of stoichiometric organometallic reagents. In this review, iridium-catalyzed C-C bond-forming hydrogenations and transfer hydrogenations are surveyed. These processes encompass selective, atom-economic methods for the vinylation and allylation of carbonyl compounds and imines. Notably, under transfer hydrogenation conditions, alcohol dehydrogenation drives reductive generation of organoiridium nucleophiles, enabling carbonyl addition from the aldehyde or alcohol oxidation level. In the latter case, hydrogen exchange between alcohols and π-unsaturated reactants generates electrophile-nucleophile pairs en route to products of hydro-hydroxyalkylation, representing a direct method for the functionalization of carbinol C-H bonds.

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“…5,6 On the other hand, the presence of an isoxazole ring that can act as a masked aldolic moiety, such as β -enamino ketone, β -diketone, etc. These groups are also of interest because they allow the synthesis of new heterocycles, for example, pyrazoles 7 that currently have great importance in pharmaceutical chemistry.…”

mentioning

confidence: 44%

Synthesis of (Isoxazol-4-ylmethyl)triphenylphosphonium Salts Derived from 5-Alkyl- and 5-Aryl-3-methylisoxazoles

Maestro¹,

Banez²,

López³

et al. 1998

Synthesis

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The synthesis of (isoxazol-4-ylmethyl)triphenylphosphonium salts derived from 5-alkyl-and 5-aryl-3-methylisoxazoles has been carried out. This method involves the preparation of several 4-(chloromethyl)isoxazoles which are suitable precusors for these phosphonium salts. The phosphonium salts were completely characterized by spectroscopic methods and were obtained in very good to quantitative yields.Chain extension in the carbohydrate series is of great interest for organic chemists. For this purpose, over the last few years several synthetic strategies have been developed. 1 Of special interest is the method employed by Dondoni 2 where D -tetrose and D -pentose derivatives were synthesized via alkenylthiazoles using 2,3-O -isopropylidene-D -glyceraldehyde as the initial substrate.With this idea in mind, our group has developed a synthetic method to 4-alkenylisoxazoles I . These compounds will be employed as key intermediates for the extension of the polyhydroxylated chain of sugars. 3In order to obtain these compounds, the synthesis of appropiate precusors such as 4-alkyltriphenylphosphonium salts II has been carried out. Their preparation is described in the present work.The use of 4-alkenylisoxazoles offers many advantages. On one hand, the easy stereocontrolled functionalization of the double bond by cis -dihydroxylation 4 or asymmetric epoxidation. 5, 6 On the other hand, the presence of an isoxazole ring that can act as a masked aldolic moiety, such as β -enamino ketone, β -diketone, etc. These groups are also of interest because they allow the synthesis of new heterocycles, for example, pyrazoles 7 that currently have great importance in pharmaceutical chemistry.The synthesis of (isoxazol-4-ylmethyl)triphenylphosphonium salts derived from 5-alkyl-and 5-aryl-3-methylisoxazoles is shown in Scheme 1.The preparation of the compounds 1-6 is carried out by two different methods. The compounds 3,5-dimethylisoxazole (1) and 3-methyl-5-phenylisoxazole (2) are obtained from the appropiate diketones by direct cyclization 8, 9 in 99% and 81% yield, respectively. Isoxazoles 3-6 are obtained from unsaturated α , β -oxo oximes according to the Alberola procedure. 10 It should be pointed out that compound 6 is obtained in low yield 11 and with trace amounts of 4-( p -dimethylaminophenyl)-4,5-dihydroisoxazole. This was not discussed in the reported procedure. 10The formation of 4-(chloromethyl) derivatives of 5-alkyland 5-aryl-3-methylisoxazoles has also been carried out by two different methods. The compound 7 , 4-(chloromethyl)-3,5-dimethylisoxazole, is obtained by the general procedure of Kochetkov. 12 However, this method does not give the desired compounds 8-11 . In these cases untransformed starting materials are recovered. The employed procedure for the preparation of compounds 8-11 is described in the experimental part (glacial acetic acid and high temperature, 100-110 ° C). The results are summarized in Table1.Although the achieved yields are moderate, this procedure has the advantage of affording the suitable C4-f...

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Stereocontrolled synthesis of D-pentitols, 2-amino-2-deoxy-D-pentitols and 2-deoxy-D-pentitols from D-glyceraldehyde acetonide

Cited by 228 publications

References 4 publications

Intramolecular ring opening of a 2,3‐epoxy alcohol by a xanthate anionic center; stereospecific preparation of 2‐mercapto‐1,3‐diol units

Intramolecular ring opening of a 2,3‐epoxy alcohol by a xanthate anionic center; stereospecific preparation of 2‐mercapto‐1,3‐diol units

Formation of C–C Bonds via Iridium-Catalyzed Hydrogenation and Transfer Hydrogenation

Synthesis of (Isoxazol-4-ylmethyl)triphenylphosphonium Salts Derived from 5-Alkyl- and 5-Aryl-3-methylisoxazoles

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