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The tandem [4 + 2] cycloaddition/pyrolytic sulfoxide elimination was developed as a general one pot synthetic process for enantiomerically enriched polycyclic dihydroquinones. Findings revealed a strong ability of the sulfoxide to regulate the regiochemistry and pi-facial diastereoselectivity of the process, being the quinone moiety responsible for the complete endo selectivity attained. The process can be used for the synthesis of optically active helicenebisquinones, provided that vinylarenes react diastereoseletively with homochiral (SS)-(2-p-tolylsulfinyl)-1,4-benzoquinone.

An indolizine, a pyrrolo(2,1-a)isoquinoline, a 1,8-diazaspiro(4,5)decane, a cyclopenta(b)-pyrrole, and an isoindoline are prepared using intramolecular addition of N,N-disubstituted hydroxylamines to unactivated olefins. Two successive reverse Cope elimination reactions were used to synthesize a pyrrolizine and a 1-azabicyclo(2.2.1)heptane from acyclic precursors. These reactions demonstrate the potential of reverse Cope elimination in the synthesis of heterocycles that contain both five- and six-membered nitrogen.

The optically-active bis(2-(1-(dimethylamino)ethyl)ferrocenyl) diselenides, (R,S;R,S) and (S,R;S,R), possess two axial and two central elements of chirality, and are good reagents for asymmetric synthesis of chiral allenes and allylic alcohols by selenoxide elimination and (2,3)sigmatropic rearrangement respectively. The chiral selenoxide is slow to racemize and proceed with little loss of optical activity which is shown by high enantioselectivities.

A method for the synthesis of a silicon-based linkage agent, SAL linker, is described. This method is developed in answer to the problems of linkage agent derived carbocations. The characterization of the SAL linker improves the percentage yield of C-terminal tryptophan-containing peptides. The linkage agent is designed to undergo deblocking by the beta-elimination process in acidic conditions.

The efficient synthesis of 2-substituted tetrahydroquinolines is achieved by the domino reaction of N-indayl(methoxy)amines, which has elimination of an alcohol, the rearrangement of an aryl group and the addition of an organolithium or magnesium reagent. The synthetic utility of the method is shown by the stereoselective formal synthesis of ([plusmn])-martinellic acid.

A variety of highly substituted thieno[3,2-c]thiopyran derivatives are furnished through L-proline-catalyzed three-component reactions of ethyl 2-[(2-oxo-2-arylethyl)sulfonyl]acetate or ethyl 2-[(2-ethoxy-2-oxoethyl)sulfonyl]acetate, aromatic aldehydes, and 5-aryltetrahydro-3-thiophenone. The facile transformations are assumed to occur via a one-pot domino sequence of enamine formation/aldol condensation/Michael addition/6-exo-trig cyclization/elimination and involved the creation in a single operation of three C-C bonds.

o-nitrophenyl sulfoxides are efficient synthetic precursors of various alkene types and the elimination has occurred in toluene and NaOAc to generate substituted and terminal alkenes. Alkene products are obtained in high purity due to the simultaneous precipitation of the o-nitrophenyl sulfenic acid byproduct and unsaturated compounds are prepared under mild, thermolytic conditions.

A convenient and highly regioselective synthesis of substituted isoquinoline derivatives from various aromatic ketoximes and alkynes via a one-pot, rhodium-catalyzed C-H bond activation is described. A probable mechanism that involves chelation-assisted C-H activation via oxidative addition of Rh(I) to an ortho-C-H bond, insertion of the alkyne, reductive elimination, intramolecular electrocyclization, and aromatization is also described.

The [beta]-alkoxide elimination reactions of propargylic ether with Negishi reagent which leads to allenes and/or alkynes after hydrolysis are reported. The coupling reactions of the allenic/propargylic zirconium intermediates with aryl iodides in the presence of Pd[(P[Ph.sub.3]).sub.4]/CuCl as a simple pathway for the synthesis of multisubstituted allenes are reported.

A rhodium-catalyzed reaction of alkynyl oxiranes with arylboronic acids to obtain syn-configured [alpha]-allenols with high diastereoselectivity is reported. The utility of the reaction which is initiated by addition of an arylrhodium(I) species onto the alkyne moiety of the alkynyl oxirane is demonstrated by an application to a concise synthesis of ([plusmn])-boivinianin B.

A modified version of the Fischer-Zach technique for the preparation of glycals from glycosyl bromides, which is performed in neutral media and therefore does not require the multiple bicarbonate washes for removal of acetic acid, is presented. The change had been described by Scheffold in which vitamin B-12 is employed as a catalyst for reductive eliminations. Hence, the Scheffold process, which utilizes methanol as solvent and ammonium chloride as a buffer together with Zn dust as a reductant, may be used in the Fischer-Zach synthesis.