Acetonide hydrolysis

Polyfunctional fluoronitro alcohois are provided by tlie SRNl reaction of a perfluoroalkyl iodide or alkylene diiodides with the anhydrous lithium salt of 2-nitropropane l,3-diol acetonide. Hydrolysis of the resulting perfluoroalkyl-... 

Conformationally constrained 2 -deoxy-4-thia /3-anomeric spirocyclic nucleosides have been synthesized by Dong and Paquette <2005JOC1580>. Osmium-catalyzed dihydroxylation of the spirocyclic dihydrothiophene 135 in the presence of DABCO gave the air-diol 136 in 53% yield which was protected as an acetonide hydrolysis using LiOH in aqueous THE and subsequent Meerwein-Ponndorf-Verley reduction of the keto compound 137 gave a diaster-eomeric mixture of alcohols (Scheme 36). 

Paquette was one of the first to apply the Wacker oxidation in the total synthesis. In his synthesis of 18-oxo-3-virgene, a constituent of the waxy surface resins of tobacco, a Wacker oxidation was deployed to convert a terminal alkene to the corresponding methyl ketone.59 In an efficient total synthesis of ( )-laurene (77), alkene 75 was oxidized to keto-aldehyde 76 at ambient temperature.60 In Smith s total synthesis of calyculin, a modified Wacker oxidation with substoichiometric cupric acetate transformed terminal alkene 78 to methyl ketone 79 without concurrent acetonide hydrolysis.61,62... 

Acetonide hydrolysis—cleavage. Terminal acetonides are selectively hydrolyzed and cleaved with HjIOs. Sometimes, a one-pot reaction can be accomplished. ... 

After conversion to aldehyde 683 (acetonide hydrolysis, tosylation, cyclization with K2CO3), oxirane ring opening with a mixed cuprate derived from 674 as in the previous synthesis cleanly gives 684. Acid-catalyzed hydrolysis of 684 forms the spiroacetal framework, and functional group manipulation leads to the desired aldehyde 685. 

The Ci-Cg and Cg-Ci3 segments [108] Routine transformations from the known pyranoside 161 led to the 2,4-dideoxyhexose 162 in five steps (Scheme 21). Moreover, 3,5-dideoxyhexofuranose 164, a Cg-Ci3 segment, was prepared from diacetonide 163 [110] by selective acetonide hydrolysis, reductive elimination of a dimesylate, and hydroboration-oxidation. 

The synthesis of 24 (Fig. 16) started with the Grignard addition to glycer-aldehyde 30 which furnished 31 with good anti-selectivity. Mitsunobu reaction, diastereomer separation by crystallization and acetonide hydrolysis gave 32, which was converted into 33 by oxidation and into 24 after hydrazinolysis. 

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