Cleavage periodate

Another method to achieve selectivity in oxidative splitting of C C bonds to carbonyl groups is controlled epoxidation followed by periodate cleavage (J.P. Nagarkatti, 1973). 

The classic method for establishing the proportion of head addition occurring in VAc polymerization involves a two step process.5 The PVAc is converted to PVA by exhaustive hydrolysis and the number of 1,2-glycol units is determined by periodate cleavage. 

A systematic investigation of the free amino acids of the Leguminosae led to the isolation of a novel ninhydrin-positive compound from the leaves of Derris elliptica Benth. (Papilionidae) (93). This substance was analyzed as C6H,3N04 (microanalysis and high resolution mass spectrometry) and was shown to be an amino alcohol. The absence of a carbonyl in the 1R, the loss of 31 mass units in the mass spectrum, and a positive periodate cleavage reaction were best embodied into a dihydroxydihydroxymethylpyrrolidine structure. The relative simplicity of the NMR spectra (three peaks in the 13C spectrum four spin-system in the H spectrum) pointed out a symmetrical structure. Inasmuch as the material was optically active ([a]D 56.4, c = 7, H20), meso structures were ruled out, and the 2R, 3R, 4R, 5R relative configuration was retained (93). This structure (53) was further confirmed by an X-ray determination (94). 

The borohydride reduction-periodate cleavage applied to 2,3-O-isopro-pylidene-D-ribono- 1,4-lactone (16a) led to L-erythrose (30). The method was also employed (31) for the synthesis of D-erythrose, starting from an Obenzylidene-D-ribonolactone. However, in this case, the structural assignments for the intermediate compounds must be revised, as the starting material formulated as 3,5-O-benzylidene-D-ribono-1,4-lactone (2) was, as discussed previously in this section, the 3,4-0-benzylidene-D-ribono-1,5-lactone (3a). Therefore, the correct structure for the product described as 3,5-O-benzylidene-D-ribitol (20, not isolated) would be 3,4-O-benzylidene-... 

Isolated double bonds can be oxidatively cleaved in systems containing a conjugated diene moiety if it is protected as a tricarbonyl(diene)iron complex44. Dienal 39 was acquired in 49% yield by a two-step osmylation-periodate cleavage sequence (equation 27). In contrast, ozonolysis of the polyene complexes is reported to lead to destruction of the complex. 

PERIODATE CLEAVAGE MALAPRADE REACTION Carbon-carbon bond formation, CROTONASE SUPERFAMILY CARBON-14 ( C)... 

PERIODATE CLEAVAGE MALAPRADE REACTION Vinculin fragment as ActA homologue, ACTIN-BASED BACTERIAL MOTILITY VINYLACETYL-CoA ISOM ERASE VINYL CATION (or Vinylic Cation)... 

Scheme 4. Richardson s application of the Fischer nitromethane cyclization to the sugar dialdehyde derived from the periodate cleavage of levoglucosan (1960).

Carbapentofuranoses could be obtained by periodate cleavage of an exocyclic diol in the isopropylidene protected carba hexofuranoses, as illustrated for 72. The protected carba pentofuranose 75 was obtained and deprotected to give carba- -D-lyxofuranose (76). 

Addition to 1-atkenes (8, 25). The critical steps in a recent synthesis of aldosterone (4) involve anli-Markovnikov addition of C6H5SeBr to I, oxidation to the allylic bromide, and acetate displacement to give 2. The corresponding 21-monoacctate was converted to the triol 3 (0s04, N-mcthylmorpholine N-oxide). The final steps to 4 involved periodate cleavage and saponification.2... 

Sowden82 recently has prepared D-glucuronic acid isotopically labeled at carbon atom 6 for certain chemical and biochemical studies. In this novel synthesis, 5-aldehydo-l,2-isopropylidene-D-xylofuranose88 (XVI), prepared by periodate cleavage of 1,2-isopropylidene-a-D-glucofuranose (XV), was condensed with Cu-labeled sodium cyanide. Alkaline... 

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