Octoses reaction

Later, pillaroside was also synthesized by reaction of 250a with388 48c and with141 50. y-Octose (29) was also synthesized by introduction of a C-vinyl group into the corresponding glycos-4-ulose.388... 

An interesting variation of the cyanohydrin synthesis is based on the application of the Strecker reaction 118], or an appropriate modification of it, to protected dialdo sugars to give glycosyl a-aminonitriles, with good levels of diastereoselectivity (ds > 90%) [19]. This approach was employed for a formal synthesis of the amino octose lincosamine from... 

Although the original paper reported1 isolation of diethyl dithioacetals of only one pentose, four hexoses, and a heptose, this reaction has subsequently been generalized, with examples ranging from trioses21 to octoses.22,23... 

Catalytic osmylation of the allylic ethers and alcohols (12) led to the octose derivative (13) as the predominant isomer the Z) alkene (14.) gave the 7-epimer (15), in agreement with the empirical rule of Kishi that there will be an erythro-relationship between the oxygens at C-5 and C-6. The reaction sequence was also extended... 

A Wittig reaction on aldehydo-2,4 5 6-tetra-0-methyl-D-glucose gave the -oct-2-enonic acid derivative (21), which yielded the lactone (22), an Intermediate for synthesizing octoses. Wittig... 

A full paper on the synthesis of octoses by the "naked sugar" approach has been published (see Vol.23, Chapter 2, ref.31). An improved, shorter version of this synthesis employs a Wittig Homer reaction instead of the original Mukayama cross-aldolization for chain-extension. Similar work has been reported by a Japanese group. ... 

Reactions.—, i-Dithianyl Anions. The Corey-Seebach 1,3-dithianyl anion rates as one of the most popular sulphur anions and nucleophilic acylating agents, as demonstrated by its recent use in the syntheses of potential precursors of the macrocyclic antitumour agent maytansine, of cyclopentenones and other unsaturated ketones,of octoses, of lla-hydrox)rprogesterone, of deuteriated aldehydes, of alnusone, of the sex-attractant of the Douglas fir tussock moth, of l,4-diketones, of 3-s-butylglutaraldehyde, of linaloyl... 

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