Sesbanimides

Sesbanimide is a novel cytotoxic compound isolated from Sesbania puni-cea seeds [84JCS(P1)1311]. According to high-field H- and C-NMR spectroscopy, in solution a solvent-dependent equilibrium exists between the... 

Figure 9. Preparation of intermediate 22 containing the B ring of the sesbanimides.

Anodic oxidation in the synthesis of piperidine alkaloids 90YGK814. Antitumor sesbanimides, total synthesis of 87YGK983. l-Azaspiro[5.5]undecane system of histrionicotoxines, syntheses of 89BSF370. 

Fleet, G W J, Shing, T, An approach to the enantiospecific synthesis of sesbanimide and its enantiomer from D-glucose, J. Chem. Soc., Chem. Commun., 835-837, 1984. 

Tomioka, K, Flagiwara, A, Koga, K, Total synthesis of (- -)-sesbanimide a from D-glucose, Tetrahedron Lett., 29, 3095-3096, 1988. 

Roush, W R, Michaelides, M R, Studies on the total synthesis of sesbanimide a highly diastereoselective synthesis of the AB ring system. Tetrahedron Lett., 27, 3353-3356, 1986. 

Sesbanimide A (34), together with its two stereoisomers sesbanimide B-l(35), sesbanimide B-2 (36) and sesbanimide C (37) all occur in Sesbania drunmondli, the structures rest on spectral and X-ray diffraction analyses. Each compound is strongly cytotoxic (R.C. Powell et al.,... 

The aqueous oxa-Diels-Alder reaction has been successfully exploited in the synthesis of sesbanimides A and B [70], carbovir [71], mevinic acids [72], aris-teromycin and carbodine [73], ketodeoxyoctulosonic acid (KDO) and analogs... 

Sesbanimides have been an attractive synthetic target. Two recent formal syntheses focused on stereoselective formation of the 1,3-dioxane ring [713] and the imide ring [714],... 

Such an aqueous hetero Diels-Alder reaction, which was extended to other dienes [42], was applied in various syntheses, including sesbanimides A and B [43], carbovir [44], mevinic acids [45], aristeromycin and carbodine [46], ketodeoxyoctu-losonic acid (KDO) and analogs [47], and sialic acids [48]. Pyruvaldehyde, glyoxal, and even ketones like pyruvic acid also react with dienes in water [42],... 

Reaction of 9 with paraformaldehyde afforded the 1,3-dioxane 10, which was subjected to oxidative hydrolysis of dithioacetal group with mercuric perchlorate to form 11, the AB ring moiety of sesbanimides 1 and 3, in 35% overall yield from 4. 

On the other hand, diacetone D-glucose was transformed to (-)- and (+)-sesbanimide A via the open chain derivative 3-0-benzyl-D-glucose diethyldithioacetal 17, which was prepared by hydrolysis of 3-C -benzyl-l,2 5,6-di-C -isopropylidene-D-glucofuranose (16) and subsequent treatment with ethanethiol in the presence of acid (Scheme 3)4 Acetonation of 17 under kinetic control followed by methylenation with dibromomethane afforded the key intermediate 1,3-dioxane 18. Deprotection of the dithioacetal unit in 18 followed by... 

---