With ceric ammonium nitrate

The DAM group, used to protect the —NH group of a /3-lactam, can be cleaved with ceric ammonium nitrate (H2O, CH3CN, 0°, 91 % yield)." ... 

The /7-nitrophenyl ether was used for the protection of the anomeric position of a pyranoside. It is installed using the Konigs-Knorr process and can be cleaved by hydrogenolysis (Pd/C, H2, AC2O), followed by oxidation with ceric ammonium nitrate (81-99% yield). ... 

For a similar reaction with ceric ammonium nitrate, see Salomon, R.G. Roy, S. Salomon, R.G. Tetrahedron Lett., 1988, 29, 769. 

Amide nitrogens can be protected by 4-methoxy or 2,4-dimethoxyphenyl groups. The protecting group can be removed by oxidation with ceric ammonium nitrate.243 2,4-Dimethoxybenzyl groups can be removed using anhydrous trifluoroacetic acid.244... 

Initially, 50 was converted into the benzoxazinone 51 by reaction with phosgene in the presence of triethylamine and 51 was isolated in 95% yield upon crystallization from methanol. Deprotection of the pMB group from 51 was accomplished with ceric ammonium nitrate (CAN) in aqueous acetonitrile. Efavirenz was isolated in 76% yield after crystallization from EtOAc-heptane (5 95), as shown in Scheme 1.19. There were two issues identified in this route. First, lequiv of ani-saldehyde was generated in this reaction, which could not be cleanly rejected from product 1 by simple crystallization to an acceptable level under the ICH guideline. Anisaldehyde was removed from the organic extract as a bisulfite adduct by washing with aqueous Na2S205 twice, prior to the crystallization of 1. Secondly,... 

Feldman and Skoumbourdis have utilized an oxidative hydrolysis of the thioimidate with ceric ammonium nitrate (CAN) to generate dibromophakellstatin 78 as the final step in their synthetic sequence (Equation 14) <20050L929>. 

A surprisingly infrequent use of Biginelli compounds to make aromatic pyrimidines has also been reported. Dehydrogenation with ceric ammonium nitrate gave pyrimidinones 23 or pyrimidinediones 24, depending on conditions <06T9726>. 

The oxidation of aromatic aldoximes with ceric ammonium nitrate produces nitrile oxides which undergo subsequent cycloaddition to nitriles to produce 1,2,4-oxadiazoles (Equation 47) <1997PJC1093>. The anodic oxidation of aromatic aldoximes in the presence of acetonitrile has been reported to give low yields of either 3-aryl-5-methyl-1,2,4-oxadiazoles (2-25%) or 3,5-bis-aryl-l,2,4-oxadiazoles (6-28%), although the synthetic utility of this route is limited by competitive deoximation to the carbonyl being the major reaction pathway <1997MI3509>. 

Only a few examples exist for the intermolecular trapping of allyl radicals with alkenes68,69. The reaction of a-carbonyl allyl radical 28 with silyl enol ether 29 occurs exclusively at the less substituted allylic terminus to form, after oxidation with ceric ammonium nitrate (CAN) and desilylation of the adduct radical, product 30 (equation 14). Formation of terminal addition products with /ram-con figuration has been observed for reaction of 28 with other enol ethers as well. 

An oxidative Mannich cyclization methodology allowed the synthesis of indolizidine skeletons. The oxidation of the a-silylamide 140 with ceric ammonium nitrate (CAN) formed in situ an iV-acylaminium cation, which cyclized to afford the bicyclic compound 141 (Scheme 35) <1998JOC841>. 

Single electron transfer nitration of epoxides with ceric ammonium nitrate... 

Unlike benzylic groups, they cannot be made directly from the alcohol. Instead, the phenoxy group must be introduced by a nucleophilic substitution.30 Mitsunobu conditions are frequently used.31 The PMP group can be cleaved by oxidation with ceric ammonium nitrate (CAN). 

Dihydropyrimidines are normally readily oxidized to the corresponding pyrimidines by dehydrogenation, hydrogen transfer, or disproportionation reactions <1994HC(52)1, 1996CHEC-II(6)93>. For example, the oxidation of a series of trifluoromethyl ketones 522 with DDQ occurred readily at room temperature <1997H(44)349>. Facile room temperature oxidation with ceric ammonium nitrate (CAN) has also been achieved <2003ARK(xv)22>. 

Cyclization of nitro-stabilized radicals provides another method for the generation of cyclic nitronates (221). Oxidation of the aci-foim of nitroalkanes with ceric ammonium nitrate generates the ot-carbon centered radical, which in the presence of an alkene, leads to the homologation of the a-radical. In the case of a tethered alkene of appropriate length, radical addition leads to a cyclic nitronate (Scheme 2.20). 

Allylic carboxylation. Diethyl oxomalonate (1) undergoes a thermal ene reaction with mono-, di-, and trisubstituted alkenes at 145 180°. The reaction is also subject to catalysis with Lewis acids, which can lead to a different ene product. The products are a-hydroxymalonic esters. The corresponding malonic acids are converted to carboxylic acids by bisdecarboxylation with NaI04 and a trace of pyridine- or with ceric ammonium nitrate (CAN). Diethyl oxomalonate then functions as an cnophilic equivalent of C02. 

The oxidative cyclization of the alcohol (214) with ceric ammonium nitrate gave a mixture of the two naphthopyrans (215) and (216) in a ratio of 3 1 (81CC534). The reaction is of interest because of the natural occurrence of quinones containing the naphtho[2,3-c]pyran ring system. 

The synthesis of antiviral spiro-(3-lactam 51 begins with the benzylation of isatin 45 to give 1-benzylisatin 46, which affords Schiff s base 47 on reaction with anisidine in ethanol. The Schiff s base 47 on treatment with methoxyacetyl chloride by the chloride-imidate cycloaddition [85] route afforded a mixture of spiro E- and Z-azetidin-2-ones 48 and 49, which were separated by chromatography. The (Z)-N-arylazetidin-2-one 49 was further converted to desired 4-spiro-(3-lactam 51 by treatment with ceric ammonium nitrate and subsequently with tetrabutylammonium bromide in THF in the presence of pulverized KOH (Scheme 13). 

---