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Ulapualide A and

Roesner, J.A. and Scheuer, P.J., Ulapualide A and B extraordinary antitumor macrolides from nudi-branch eggmasses, J. Am. Chem. Soc., 108, 846, 1986. [Pg.223]

Chattopadhyay, S.K. and Pattenden, G. (1997) A convergent synthesis of the tris-oxazole ring system in ulapualide A and related marine metabolites. Synlett, 1342-1344. [Pg.1460]

Several nitrogen-containing macrolides were reported to be obtained from marine sources. Ulapualides A (254) and B (255), possessing unique structures with three contiguous oxazoles, were isolated from the egg... [Pg.76]

The eggs of the nudibranch Hexabranchus sanguineus collected off the coast of Hawaii have yielded the macrolides ulapualide A (62) and ulapaulide B (63) (25) both of which incorporate the unprecedented trisoxazole moiety. These compounds were obtained as colorless oils whose structure determination was... [Pg.269]

The structural diversity of molluscan chemistry can be seen in compounds 32-40 in Scheme 6.2 and includes a number that have been included in clinical studies such as the kahalalides and the dolastatins 34 and 37. An example of material exchange from prey to predator can be shown in kahalide F 32, which can be found in both the sea hare Elysia sp. and its diet of Bryopsis sp. algae. In addition, the structural similarity of ulapualide A 23 and that of the compounds mycalolide 21 and halichondramide 22 (Scheme 6.1 Part 3), found in a diverse array of sponges, indicates a possible alternate source for this structure class. [Pg.187]

In the late 1980s, ulapualide A 23 was isolated from the egg masses of the nudibranch Hexabranchus sanguineus120 and was shown to inhibit the growth of Candida albicans and L1210 leukaemia cell proliferation. A molecular mechanics study initially suggested that the relative stereochemistry was related to that of the halichondramides and mycalamides,350 however, the... [Pg.188]

A new synthesis of (-)-ulapualide A was completed by the group of Pattenden following a previous synthesis of a different diastereisomer whose chiroptical and H NMR spectroscopic data were identical with those of the natural product <07 AG(E)4359>. The first synthesis of siphonazole 119 was completed. Both the oxazole rings were constructed using rhodium carbene chemistry <07CC1508>. [Pg.277]

Chattopadhyay, S.K., and Pattenden, G., Towards a total synthesis of ulapualide A. A concise synthesis of the fm-oxazole macrolide core and entire carbon skeleton, Synlett, 1345, 1997. [Pg.397]

In the total synthesis of filipin III (141) [95], macrocyclization under K2CO3/ 18-crown-6 conditions proceeded (Fig. 4), although the cyclization was unsuccessful under LiCl/DBU conditions, which were useful for roflamycoin (140) [94] and roxaticin [93]. The total synthesis of ulapualide A (142) was accomplished via three Wittig-type couplings [101]. [Pg.201]

Panek and co-workersdescribed syntheses of suitably bis-functionalized tris-oxazoles as intermediates leading to kabiramide C, halichondramide, and ulapualide A based on sequential application of a modified Hantzsch condensation methodology (Scheme 1.395). For example, condensation of cinnamide with ethyl... [Pg.348]

Panek s group ° employed the Schlosser-Wittig olefination reaction of an in situ-generated tris-oxazole phosphonium salt to incorporate the trans double bond of an advanced intermediate leading to ulapualide A (Scheme 1.397). Model studies that precedent this work were described in Scheme 1.298. Thus reaction of 1560 with 1561 in the presence of excess triethylphosphine and one equivalent of LDA generated 1562 in excellent yield as a single double-bond isomer. This result was noteworthy in that it demonstrated the viability of this type of bond construction in the presence of a potentially labile p-alkoxy substituent. [Pg.350]

Cleavage of Protecting Groups. THP ethers of primary, secondary, and phenolic alcohols can be conveniently de-protected at room temperature by treatment with 1.2 equiv of TMSOTf in methylene chloride (eq 96). Deprotection of tert-butyldimethylsilyl ethers in the presence of a tert-butyldiphenylsilyl ether has been smoothly accomplished using TMSOTf at —78°C, as one of the steps of the total s)mthesis of marine macrolide ulapualide A. ... [Pg.536]

Pattenden, G., Ashweek, N.J., Baker-Glenn, C.A.G., Kempson, J., Walker, G.M., and Yee, J.G.K (2008) Total synthesis of (-)-ulapualide A, a novel tris-oxazole macrolide from marine nudibranchs, based on some biosynthesis speculation. Org. Biomol. Chem., 6,1478-1497. [Pg.1460]

Panek, J.S. and Beresis, R.T. (1996) Studies directed toward the synthesis of ulapualide A. Asymmetric synthesis of the C8-C25 tris-oxazole fragment/. Org. Chem., 61, 6496-6497. [Pg.1460]

Chattopadhyay S.K. and Pattenden, G. (1998) Total synthesis of ulapualide A, a novel tris-oxazole containing macrolide from the marine nudibranch Hexabranchus sanguineus. Tetrahedron Lett., 39, 6095-6098. [Pg.1460]

Asymmetric organocatalyzed hydride transfer was utilized in the total syntheses of spUceosome inhibitor 901464 [102], (-t) neopeltoMe [103], iriomoteolide-lb [104], (-i-)-neopeltolide [103], dysideaproline E [105], and ulapualide A [106]. For theoretical calculations on the origin of stereoselectivity of this process see Reference [107]. [Pg.86]

The compounds isolated from the nudibranch Hexabranchus sanguineus varied with collecting location but usually included dihydrohalichondra-mide (261) and tetrahydrohalichondramide (268). Compounds 261, 263, 265, and 268 show antifungal activity and inhibit cell division in the fertilized sea urchin egg assay (218). Three cytotoxic macrolides, mycalolides A-C (269-271), were isolated from a Japanese sponge of the genus My-cale, and their structures were elucidated to be hybrids of ulapualides and halichondramide (219). [Pg.80]


See other pages where Ulapualide A and is mentioned: [Pg.335]    [Pg.295]    [Pg.189]    [Pg.56]    [Pg.93]    [Pg.1441]    [Pg.2035]    [Pg.335]    [Pg.295]    [Pg.189]    [Pg.56]    [Pg.93]    [Pg.1441]    [Pg.2035]    [Pg.189]    [Pg.489]    [Pg.16]    [Pg.315]    [Pg.42]    [Pg.71]    [Pg.13]    [Pg.248]    [Pg.262]    [Pg.345]    [Pg.44]    [Pg.1460]    [Pg.1460]    [Pg.1991]   
See also in sourсe #XX -- [ Pg.269 , Pg.295 , Pg.300 ]

See also in sourсe #XX -- [ Pg.16 ]

See also in sourсe #XX -- [ Pg.16 , Pg.17 ]

See also in sourсe #XX -- [ Pg.16 , Pg.17 ]




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