Amino cleavage, oxidative, with

The involvement of an aldehyde-enolate as a ligand on IBX has also been postulated in a first oxidative C C bond cleavage reaction using IBX. N-Protected amino alcohols 14 have been oxidized with IBX in DMSO to the corresponding imides 15 [17]. 

Rearrangement of optically active allylic selenides98 2, derived from enantiomerically pure (S)-lactate and subsequent oxidative cleavage of the double bond, leads to D-amino acids 4 with 78-84% ee. The loss of optical purity is the result of difficulties in synthesizing enantiomerically and diastereochemically pure allylic selenides with Z configuration, rather than the result of incomplete chirality transfer of the rearrangement. 

Camarero et al. [108] used the hydrazine safety-catch linker to prepare peptide thioesters. After assembling the peptide using standard Fmoc protocols, the fully protected peptide resin was activated by mild oxidation with N-bromosuc-cinimide (NB S) in the presence of pyridine, forming a reactive acyl diazene that was then deaved with an a-amino add S-alkyl thioester such as H-AA-SEt, where AA is Gly or Ala. After TFA deprotection, peptide thioesters were obtained in good yields. Although the oxidation step did produce racemization, and other sensitive amino acids such as Tyr(tBu) and Trp(Boc) were not affected, Met and Cys presented some problems. Met was completely oxidized, and a reductive cleavage was required. For Cys, the Cys(Trt) derivative should be avoided and use of Cys(Npys) or Cys(S-StBu) is recommended instead. 

Amino acids. Oxidation of aliphatic primary amines with ruthenium tetroxide leads to complex products. However, oxidation of aralkylamines at pH 3.0 with periodate (12 eq.) and RuCls 3H2O (0.02 eq.) converts the aromatic ring into a carboxyl group to give amino acids. Cleavage is facilitated by a 4-methoxy or hydroxy substituent in the ring. ... 

The previously suggested structure (71) for isolongistrobine has been confirmed by synthesis (Scheme 4). TTie amino-alcohol (69) available from related synthetic work (see Vol. 4 of these Reports), was acylated with 4-pentenoyl chloride to give (70), which upon successive oxidation with Cornforth s reagent and oxidative double-bond cleavage with sodium periodate-osmium tetroxide gave isolongistrobine (71)-... 

Nitro-ketones, particularly cyclic derivatives, are important sources of amino acids since the nitro group can be reduced to an amino group (see chapter one, section l.l.B). In one example, cyclohexene was treated with nitrogen dioxide (N2O4) and the product was oxidized with chromium trioxide to give 2-nilrocyclo-hcxanone 2.13). When 2.13 was treated with aqueous bicarbonate, cleavage of the... 

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