3,4 5,6-di-O-isopropylidene

CisH2407 (1 S)-5,7-Anhy dro-8-deoxy-1,2 3,4-di-O-isopropylidene-aZde-hydo-D-glycero-D-galacto-octos-6-methyl acetal AGLGAO 37 399... 

P. Borrachero, M. J. Dianez, M. D. Estrada, M. Gomez-Guillen, A. Gomez-Sanchez, A. Lopez-Castro, and S. Perez-Garrido, Silica gel-catalysed addition of methyl nitroacetate to 1, 2 3, 4-di-O-isopropylidene-a-D-ga/acto-hexodialdo-... 

I, 5-pyranose and 2, 3-0-isopropylidene-D-glyceraldehyde. Crystal structure of methyl 7-acetamido-7-deoxy-1,2 3,4-di-O-isopropylidene-L-t/ireoa-D-ga Zacto-octopyranuronate, Carbohydr. Res., 271 (1995) 79-99. 

The Arbuzov reaction has been applied for the synthesis of fluorinated carbohydrates. 1,2 3,4-Di-O-isopropylidene-a-D-galactopyran-ose 6-(N,N-diethyl-P-methylphosphonamidite) was treated with ethyl fluoroacetate, to afford 6-deoxy-6-fluoro-l,2 3,4-di-O-isopropylidene-a-D-galactopyranose in 19% yield.241 The corresponding 6-deoxy-6-fluoride was obtained in 60% yield by treatment of l,2 3,4-di-0-isopropylidene-a-D-galactopyranose 6-(dipropylphosphinite) with hexafluoropropene.242 The mechanism of this reaction has been discussed.243,244 In contrast, treatment of 1,2 -.3,4-di-O-isopropylidene-a-D-galactopyranose 6-(tetraethylphosphorodiamidite) with benzoyl fluoride yielded the corresponding 6-benzoate, not the 6-deoxy-6-flu-oride expected.245... 

LAH complexes of the monohydroxy carbohydrate derivatives 1,2 3,4-di-O-isopropylidene-a-D-galactopyranose (39) and 1,2 5,6-di-O-isopropylidene-a-D-glucofuranose (40) have been reported to effect asymmetric reduction of... 

G. E. Driver and J. D. Stevens, Septanose carbohydrates. III. Oxidation-reduction products from 1,2-3,4-di-O-isopropylidene-a-D-glucoseptanose Preparation of L-idose derivatives, Aust. J. Chem., 43 (1990)2063-2081. 

Kent and coworkers98 have reported that N-(2-chloro-l,l,2-tri-fluoroethyl)diethylamine (51) reacts with l,2 3,4-di-0-isopropylidene-a-D-galactopyranose (42) in N,N-dimethylformamide at 60°, in the presence of anhydrous potassium fluoride, to give a mixture from which 6-chloro-6-deoxy-1,2 3,4-di-O-isopropylidene-a-D-galactopyra-... 

Replacement can also be caused at a -primary carbon atom thus, 1,2 3,4-di-O-isopropylidene-6-O-tosyl-D-galactose reacts122 with anhydrous hydra-... 

No optically active derivatives of epi-inositol have been prepared. All asymmetrically substituted compounds listed in this Table are racemic. 6 p-aminoben-zoyl-.c p-nitrobenzoyl-. d Derived from the corresponding 5,6-di-O-acylated 1,2 3,4-di-O-isopropylidene-epi-inositols. Change of numbering (but not shift of groups) takes place on removal of the isopropylidene groups. 

One method to overcome selectivity issues during telomerization is to chemically protect all but one alcohol functionality. The first example of telomerization with a protected sugar was performed by Zakharkin et al., who successfully telo-merized 1,3-butadiene with the primary alcohol of 1,2,3,4-di-O-isopropylidene-ot-D-galactopyranose [93]. 

An Evaluation of Methods for the Preparation of 1,2 3,4-Di-O-isopropylidene-a-D-galacfo-hexodialdo-l,5-pyranose. Oxidation of l,2 3,4-Di-0-isopropylidene-a-D-ga-lactopyranose with Lead Tetraacetate-Pyridine, D. J. Ward, W. A. Szarek, and J. K. N. Jones, Carbohydr. Res., 21 (1972) 305-308. 

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