Sesbanimide synthesis

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. 

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... 

Synthesis from o-threose The synthesis of ring A in sesbanimide A (1) was constructed by treatment of 51, obtained from D-threose derivative 50, with lithium trimethylsilylacetonitrile to afford exclusively 52 in quantitative yield (Scheme 7) The latter underwent desilylation with CsF to produce the ester 53 in 94% yield. Hydrolysis of the cyanide group in 53 followed by imide formation afforded 54 (47%). 

Synthesis from o-mannitol The AB ring of sesbanimide was also synthesized from cyclohexyhdene D-glyceraldehyde 57, readily available from D-mannitol (Scheme 8). ° The addition of (Z)-7-alkoxyallylboronate 56, prepared from 55, to 57... 

Synthesis of the natural (+)-sesbanimide A (1) from D-xylose, employing a similar method to that used above for 2, has been achieved " starting with 43. 

The D-glucose derivative (49) serves as a convenient source for preparing both enantiomers of the precursor (50) for the antitumour compound sesbanimide. Scheme 11 outlines the synthesis of the D-enantiomer the L-form was obtained by demasking the aldehyde at... 

Last year saw the application of D-xylose to the synthesis of sesbanimide and this strategy has been extended to encompass ring C variants. A new synthesis of the cosmetic component 70 (a well-studied synthetic target that is derived from the civit cat) from 3,4-di-O-acetyl-L-rhamnal has been developed and the same group have described the use of L-rhamnal for synthesis of L-oleandrose 71. Methyl 6-deoxy-2,3-0-isopropylidene-a—D-mannopyranoside provides a flexible precursor to a series of deoxysugars (tetrahydropyrans), a-D-amicetoside 72, a-D-perosaminoside 73 and a-D-janoside 74.49... 

There has been a further report concerned with the synthesis of (+)-sesbanimide, in which a popular intermediate derived from D-xylose (see Vol. 19, p. 268) has been manipulated in a novel manner, involving a tricyclic intermediate. 1... 

A further synthesis of the bioactlve (+)-enantiomer (44) of sesbanimide has been reported, with the carbon framework of D-glucose being incorporated as shown, and a full account has been given of an alternative route to (44) and its (-)-enantiomer from the enantiomeric jqrloses (see Vol. 19, p.261, and V0I.2O. p.268).44... 

Michael Addition. The reaction of a, 8-unsaturated aldehydes andketones with trimethylsilylacetonitrile proceeds with 1,2- and 1,4-regioselectivity, respectively. A synthesis of (+)-sesbanimide highlights the utility of trimethylsilylacetonitrile in a Michael addition to an o(, -unsaturated ester lithiotrimethylacetonitrile gives exclusively the 1,4-addition product, whereas lithioacetonitrile gives mainly the 1,2-addition product. Desilylation of the former adduct results in the product of overall 1,4-addition of lithioacetonitrile. 

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