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Synthesis of juvabione

Chemical Synthesis of Hormones, Pheromones and Other Bioregulators [Pg.84]


Ketone (31) was used in a synthesis of juvabione (32) an insect hormone mimic produced by conifers. [Pg.429]

Another example of a synthesis of a 1,6-D system is found in the key step of the synthesis of juvabione (38), also by Evans [26], which proceeds through a base catalysed [3,3]-sigmatropic oxy-Cope rearrangement (Scheme 5.23). [Pg.139]

Hydroboration of limonene with disiamylborane followed by oxidation afforded the isomeric alcohols as 3 2 mixture. These starting materials are utilized in the synthesis of juvabione isomers2101 and in the synthesis of beetle defense substances, chrysomelidial 211), plagiolactone 212) and dehydroiridodial213) (Scheme 6). [Pg.78]

The key step in total synthesis of (+)-Juvabione by G. Helmchen and co-workers was the Pd-catalyzed allylic... [Pg.273]

A simple and efficient synthesis of juvabione (58) (c/. Vol. 1, p. 60 Vol. 5, p. 49 Vol. 4, p. 88), a sesquiterpenoid possessing juvenile hormone activity, has been achieved using a combination of hydroboration and carbonylation reactions cf. Scheme 6). A new efficient synthesis of ( )-a-curcumene (59) cf. Vol. 5, p. 51) involves reduction in situ (Li-NHs) of the alkoxide produced from p-tolylmagnesium bromide and 6-methylhept-5-en-2-one. ... [Pg.59]

Kawamura, M., and Ogasawara, K.. Stereo- and enantio-controlled synthesis of (+)-juvabione and (+)-epijuvabionc from (+)-norcamphor. J. Chem. Soc.. Chem. Commun., 2403, 1995. [Pg.486]

There are of course many kinds of stereoselectivity not involving the aldol reaction and many will appear in the rest of the book. Just for example, we give a recent synthesis of juvabione,... [Pg.51]

Acylation of the acid chloride of 75 with a Grignard reagent catalysed by Fe(III) completes a synthesis of juvabione 76 with good stereochemical control. [Pg.53]

Figure 3.2 Synthesis of ( )-juvabione. Modified by permission of Shokabo Publishing Co., Ltd... Figure 3.2 Synthesis of ( )-juvabione. Modified by permission of Shokabo Publishing Co., Ltd...
Metallation of l-methoxy-2-butyne with n-butyllithium at -78 C, followed by the addition of one equivalent of zinc chloride, generates the very reactive and unisolable organozinc intermediate. Reaction of this zinc reagent with cyclohexenone affords the alkynic alcohol in 95% yield as a 65 35 mixture of diasteieomers. Subsequent reduction of the triple bond provides either the trans alkene or the cis alkene, depending on the reaction conditions. A modified oxy-Cope rearrangement thus provides the dia-steieomeric ketones, which have been used for the synthesis of juvabione (Scheme 29). ... [Pg.91]

Bridged ketone (52) was used in a synthesis of juvabione (see Chapter 38). The common atoms are marked and disconnection of any bond to one of these atoms will give a starting material with only one ring. [Pg.317]

Camphoric acid (41) is stiil cyclic, but the method applies equally well to open ch n compounds. The two chiral centres in juvabione (42), the compound produced by some conifers as a chemical defence against moths, are on a flexible part of the molecule and cannot easily be controlled. Monti s synthesis of juvabione used a c e compound to fix the stereochemistry. [Pg.332]

This reaction was used in one step in a synthesis of juvabione (2), a juvenile hormone mimic, from pcrillaldchydc (1). [Pg.361]

The value of using bivalent conjunctive reagents can be seen in a building block oriented synthesis of juvabione (39) [19] (Scheme 5.8). [Pg.77]

Scheme 5.8 Use of a 7,7-bivalent conjunctive reagent in the synthesis of juvabione... Scheme 5.8 Use of a 7,7-bivalent conjunctive reagent in the synthesis of juvabione...
Itagaki N, Iwabuchi Y (2007) Enantio- and Diastereocontrolled Synthesis of (+)-Juvabione Employing Organocatalytic Desymmetrisation and Photoinduced Fragmentation. Qiem Commrm 1175... [Pg.218]

Trost, B. M. Tamaru, Y. "2-Methylthioacetic Acid and Diethyl Mabnate as Acyl Anion Equivalents. Synthesis of Juvabione" Tetrahedron Lett. 1975, 3797-3800... [Pg.187]

NegishI, E, Sabanski, M, Katz, J.-J. Brown, H, C. "An Efficient Synthesis of Juvabione and Todomatuic Acid via Hydroboration-Oxidation" Tetrahedron 1976, 32,925-926. [Pg.187]

Nagano, E. Mori, K. "Synthesis of (+)-Juvabione, a Compound with Juvenile Hormone Activity" Biosci. Biotech. Biochem. 1992, 56,1589-1591... [Pg.189]

Another enantioselective route to 116, that features catalytic asymmetric induction, is shown here (see Prostaglandins-12 for another example). This synthesis begins with racemic allylic acetate 123. A palladium-mediated ally-lation of dimethyl malonate in the presence of chiral ligands (for the Pd) provided 124 with excellent enantioselectivity. This material was converted to 116. Alkylation as per the Mori synthesis (Juvabione-16) gave 117, which was converted to 125 using another Pd-mediated malonate allylation. Malonate 125 was converted to 126 via an intermediate tetraol. The synthesis of juvabione (15) was then completed using a short reaction sequence. [Pg.192]

Let s look at another alkaloid whose structure screams Mannich reaction for an endgame. Luciduline is one member of the Lycopodium family of alkaloids. This is a large family of natural products. A few structures are shown here (50-54). Luciduline (55) is a )8-aminoketone. This is precisely the difunctional relationship that results from the Mannich reaction. Thus, a strategy that passes through 56 en route to 55 seems likely to succeed. Aminoketone 56 is a 1,5-difunctional compound and, in principle, should be available using normal carbonyl chemistry. We will see an example of this later, but the first synthesis of luciduline approached 56 from 1,6-difunctional intermediate 57. One versatile method for the preparation of 1,6-dicarbonyl compounds is the oxy-Cope rearrangement. We saw this in the Evans synthesis of juvabione (Chapter 5) and indeed, this is the methodology used by Evans and Scott in their synthesis of luciduline (58 57). [Pg.291]


See other pages where Synthesis of juvabione is mentioned: [Pg.295]    [Pg.295]    [Pg.297]    [Pg.821]    [Pg.948]    [Pg.453]    [Pg.453]    [Pg.623]    [Pg.198]    [Pg.821]    [Pg.51]    [Pg.82]    [Pg.84]    [Pg.453]    [Pg.181]    [Pg.185]    [Pg.191]   


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Juvabione, synthesis

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