Epimerization of bicyclic vinyl tertiary-alcohols via [2,3] sigmatropic rearrangement

General methods for inverting the stereochemisty of vinyl $\text{tertiary}$-alcohols such as $\text{2}$ and $\text{5}$ into $\text{3}$ and $\text{8}$ respectively are described. The procedures employ a [2,3] sulfoxide rearrangement and will facilitate the extended use of the oxy-Cope rearrangement to a variety of related ring systems.     

[2+2] Cycloaddition of benzyne to cis,trans- and cis,cis-1,5-cyclooctadiene

The relative rates of formation of $\text{cis}$ and $\text{trans}$ [2+2]cycloadducts of benzyne to $\text{cis}$, $\text{trans}$- and $\text{cis}$, $\text{cis}$-1,5-cyclooctadiene, $\text{trans}$- and $\text{cis}$-cyclooctene are discussed and properties of the adducts (e.g., their unusual hydrogenation) are described.     

Stereoselective synthesis of (1R,3R,5S-1,3-dimethyl-2,9-dioxabicyclo[3.3.1]nonane

(1$\text{R}$,3$\text{R}$,5$\text{S}$)-1,3-Dimethyl]-2,9-dioxabicyclo[3.3.1]nonane $\text{1}$ has been stereoselectively synthesized based on a highly stereoselective method for the synthesis of 1,3-$\text{syn}$-polyol.     

Synthesis of the enantiomeric forms of cis and trans 1-benzyloxy-2,3-epoxy butane and of (3S,4S) 4-methyl-3-heptanol

The C₄erythro and threo diols (7) and (8) are converted either into the chiral epoxides (13) and (15) or into the enantiomers (14) and (16); the epoxide (13) is used as chiral synthon for the preparation of (3$\text{S}$,4$\text{S}$) 4-methyl-3-heptanol (21).     

Stereospecific synthesis of Z- and E-1 alkoxy-1,3-butadienes

A stereospecific, highly efficient, generally applicable synthesis of $\text{Z}$- and $\text{E}$-1-alkoxy-1,3-butadienes involving dehydrative decarboxylations of 4,5-unsaturated-2-alkoxy-3-hydroxy-carboxylic acids is described.     

Boat-chair conformational preference of exo, exo-9-oxobicyclo[3.3.1]nonane-2,4-dicarboxylic acid

The ¹H and ¹³C nmr spectra of $\text{exo}$, $\text{exo}$-9-oxobicyclo[3.3.1]nonane-2,4-dicarboxylic acid, 3, in DMSO-d₆ or alkaline D₂O, clearly show that it exists in a $\text{boat}$-$\text{chair}$-conformation with $\text{equatorial}$ carboxyl groups, thus being the first case of $\text{boat}$-$\text{chair}$ preference of a bicyclo[3.3.1] nonan-9-one due to the presence of $\text{exo}$,$\text{exo}$-2,4- substituents.     

Synthesis of N-benzoyl L- and D-2,3,6-trideoxy-3-aminoxylo-hexose from non-carbohydrate precursors

The enantiomeric alcohols ($\text{2}$) and ($\text{11}$), obtained from (2$\text{R}$,3$\text{R}$) tartaric acid and, respectively, $\text{L}$-threonine, have been used to construct the C₆, enantiomeric deoxy amino sugar derivatives ($\text{7}$) and ($\text{12}$)     

The synthesis of 3-vinylindoles and 11H-5-cyanobenzol[a]carbazole

The synthesis of 3-vinylindoles through Wadsworth Emmons reactions with 3-formyl and 3-acylindoles is described. Although 3-formylindoles react directly with phosphonate derivatives, 3-acylindoles need prior activation by N-sulphonation. 11$\text{H}$-5-Cyanobenzo[$\text{a}$]carbazole has been prepared by the oxidative cycloaddition of $\text{E}$-3-(indol-3′-yl) propenotrile and benzyne.     

A one-step transformation of aromatic aldehydes to nitriles,using S,S-Dimethylsulfurdiimide as iminating agent. Isolation of dithiatetrazocines as reaction intermediates.

$\text{S}$,$\text{S}$-Dimethylsulfurdiimide is explored as a novel and effective reagent for the direct synthesis of aromatic nitriles from aldehydes. A novel eight-membered heterocycle is isolated as a reaction intermediate and a mechanism for this reaction is discussed.     

Stereocontrolled synthesis of either (22S)- or (22R)-hydroxy-23-acetylenic steroid side chains via [2,3]-Wittig sigmatropic rearrangement

A unified approach to either (22$\text{S}$)- or (22$\text{R}$)-hydroxy-23-acetylenic steroid side chains is described which relies on the concept of the stereochemical transmission via the [2,3]-Wittig sigmatropic rearrangement.