A direct method for preparing 2,3-epoxyamides from tertiary allylamines via a tandem C-H oxidation/double bond epoxidation using sodium chlorite is reported. Apparently, the reaction course consists of two steps: (i) allylic oxidation of the starting allylamine to corresponding unsaturated allylamide with sodium chlorite followed by (ii) epoxidation of the allylamide to the 2,3-epoxyamide mediated by hypochlorite ion, which is formed in situ by reduction of sodium chlorite. The reaction conditions tolerate the presence of free hydroxyl groups and typical functional groups such as TBS, aryl, alkyl, allyl, acetyl, and benzyl groups; however, when an activated aromatic ring (e.g., sesamol) is present in the substrate, the use of a scavenger is necessary.

A dienamine mediated asymmetric Diels–Alder reaction between an array of α,β-unsaturated enals and electron-deficient pyrones is presented along with further transformations of the obtained products and models for the observed stereoselectivity.

thiazolidine-2-thiones. This chiral induction proved to be strikingly effective for asymmetric syntheses of various C1-/3-substituted carbapenems.Supplementary Material Available: Tables of crystal data of compound 10b, atomic parameters for non-hydrogen atoms, fractional coordinates for hydrogen atoms, anisotropic thermal parameters for non-hydrogen atoms, bond length and valance angles, torsion angles, and observed and calculated structure factors in compounds 10b, the perspective view for the crystallographic structure of 10b, and experimental details and results in the reaction of 2 with 3 (or dl-13) (10 pages). Ordering information is given on any current masthead page.

A series of five-, six-, seven-, and eight-membered lactams containing the chiral auxiliary α-methylbenzylamine were structurally analyzed and further studied by DFT calculations with the purpose to examine with detail the previously detected intramolecular C-H···O hydrogen-bonding interaction formed between the hydrogen atom of the α-methylbenzylamine and the carbonyl group of the cyclic amide. The main objective was to establish whether its presence does have a tangible relevance in their spatial arrangement in solution and in the solid state or is a simple and not stabilizing interaction.

The reactions of a variety of ester and lactone enolates with methyldiphenylchlorosilane were studied. The Cversus O-silylation, leading to the -silyl ester or lactone and silyl ketene acetal, respectively, was studied as a function of the structure of the ester or lactone and the reaction conditions. It was found that all simple acetates are C-silylated irrespective of the steric demands of the alcohol portion of the ester. Esters that are monosubstituted in the -position are cleanly C-silylated with the notable exceptions of ethyl phenylacetate and ethyl phenoxyacetate, both of which give mixtures of C-and O-silylation. The , -disubstituted esters give only O-silylation, but the a,«-substituted -silyl esters are readily prepared by the alkylation of the appropriate monosubstituted -silylated ester. The reaction of the lithium enolate of ethyl acetate and ierf-butyl acetate with (S)-(-)-l-naphthylphenylmethylchlorosilane showed the reaction to occur with inversion of configuration at silicon. Methylation of fert-butyl (1 -naphthylphenylmethylsilyl)acetate gave a 91:9 mixture of diastereomeric -silyl propionates, which could not be separated. It was found that only the y-lactones gave C-silylation with -valerolactone and e-caprolactone giving O-silylation.The silylation of ester or lactone enolates can occur to produce the silyl ketene acetals or the -silyl esters or lactones, all synthetically useful classes of compounds, as a result of silylation at the Oor C-terminus of the enolate

Remote and multiple functionalization of piperidines without the use of transition‐metal catalysts and elaborate directing groups is one of the major challenges in organic synthesis. Herein is reported an unprecedented two‐step protocol that enables the multiple functionalization of piperidines to either 4‐substituted or trans‐3,4‐disubstituted 2‐piperidones. First, by exploiting the duality of TEMPO reactivity, which under oxidative and thermal conditions fluctuates between cationic and persistent‐radical form, a novel multiple C(sp3)‐H oxidation of piperidines to α,β‐unsaturated 2‐piperidones was developed. Second, the intrinsic low reactivity of the unsaturated piperidones toward conjugated Grignard additions was overcome by using trimethylsilyl chloride (TMSCl) as Lewis acid. Subsequently, conjugated Grignard addition/electrophilic trapping protocol provided substituted 2‐piperidone intermediates, some of which were then transformed into pharmaceutical alkaloids.

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