Wittig-horner reaction of a phosphonate of reissert analogue a new method for introduction of alkyl groups into isoquinoline

Dimethyl 2-isopropoxycarbonyl-1, 2-dihydroisoquinoline-1-phosphonate ($\text{1}$) was prepared from isoquinoline, isopropyl chloroformate, and trimethyl phosphite. Wittig-Horner reaction of $\text{1}$ with various aldehydes afforded the corresponding exo-methylene compounds, which were converted to 1-substituted isoquinolines with hydrogen chloride.     

Reduction of olefinic bond under ammonia chemical ionization

The unsaturated $\text{trans}$dicarboxylates (III and IV) form stable (M+N₂H₇)⁺ adducts in addition to the (M+NH₄)⁺ adduct. At high ammonia pressure in the ion source, bimolecular reactions between (M+NH₄)⁺ (M+N₂H₇) adducts and NH₃ result in the reduction of olefinic bonds in unsaturated $\text{cis}$ and $\text{trans}$ dicarboxylates. Evidence was obtained from MIKE/CAD data on the possible structure of the product ion.     

A nitrosamine route to (±)-macrostomine

In a synthetic approach to macrostomine $\text{1}$, both side chains of the isoquinoline nucleus are attached by high yield carbon carbon bond formation with lithiated nitrosamines ($\text{2b}$ → $\text{3a}$, $\text{3c}$ → $\text{4a}$).     

Synthetic studies in the β-carboline area new entry into4-substituted and 3,4-disubstituied β-carbolines

The [3,3] sigmatropic rearrangement of the allyl ether $\text{2}$ to provide $\text{3}$ represents a new synthetic entry into 3,4-disubstituted β-carbolines. In keeping with the interest in such substituted β-carbolines, the hydrazine mediated conversion of 4-oxo-tetrahydro β-carboline $\text{1b}$ into 4-amino β-carboline $\text{2b}$ is also described, as well as the analogous reaction in the isoquinoline series.     

Renierone,an antimicrobial metabolite from a marine sponge

The major antibacterial metabolite in the sponge $\text{Reniera}$ sp. was shown to be an isoquinoline quinone, renierone ($\text{1}$). The structure of renierone ($\text{1}$) was defined by X-ray crystallography.     

E- or Z-selective Horner-Wittig reactions of substituted bicyclo[3.3.0]octane-3-ones with chiral phosphonoacetates

The Horner-Wittig reaction of substituted bicyclo[3.3.0]octane-3-ones with chiral phosphonoacetates 2 gave the corresponding unsaturated esters in $\text{E}$/$\text{Z}$-ratios of up to 91 : 9.     

Steroidal antifeedants from the dorid nudibranch Aldisasanguineacooperi

Two steroids, 3-oxo-chol-4-ene-24-oic acid ($\text{2}$) andi ts unsaturated analog $\text{4}$ have been isolated from the dorid nudibranch $\text{Aldisa}$$\text{sanguinea}$$\text{cooperi}$, and the acid $\text{2}$ has been shown to have antifeedant properties.     

Ring cleavage rearrangement of cyclobutylmethylboranes

Boranes derived from hydroboration of methylenecyclobutane with borane/THF, 9-borabicyclo[3.3.1]nonane, and borane-methyl sulfide rearranged on heating in situ at 100–160°C to open chain structures. Products after oxidation were the unrearranged cyclobutylmethanol, and 4-penten-1-ol, 1,4-pentanediol and 1,5-pentanediol. The unsaturated alcohol was the major product in reactions with a stoichiometric ratio of alkene to BH bonds, and the diols were formed with excess borane. With borane-methyl sulfide as hydroborating reagent, the rate of rearrangement at 100°C in triglyme was not significantly dependent upon the initial alkene/borane ratio $\text{3}\text{1}$ or $\text{1.15}\text{1}$ or the presence of excess methyl sulfide. However, an equivalent amount of pyridine prevented rearrangement. Rearrangement in THF using borane/THF also occurred at comparable rates in the presence and absence of excess borane. Little or no isomerization of the boron function into the cyclobutane ring was observed. Results are interpreted on the basis of a concerted four-center mechanism which requires a vacant boron orbital.     

Thiosulfonium ions. Methylthiolation of 3-methylthio-1-butene and cis- and trans-1-methylthio-2-butene

Whereas sulfenyl reagents commonly add to carbon double bonds, addition to sulfur of 3-methylthio-1-butene precedes attack at carbon to give allylic thiosulfonium ions that form reversibly and which rearrange rapidly to $\text{trans}$-2-butenyl analogs. Likewise, rearrangement of $\text{cis}$- to $\text{trans}$-1-methylthio-2-butene occurs by way of thiosulfonium ions.     

The formation and subsequent cyclisation of novel hydroperoxides from a 1,4− and a 1,5-diene

The preparation of the unsaturated hydroperoxides ($\text{3}$,$\text{4}$,$\text{5}$,$\text{6}$ and $\text{7}$) by the sensitized photooxidation of the 1,4-diene($\text{1}$) and the 1,5-diene($\text{2}$) is described, together with the attempted free-radical cyclisation of these.     

Carbopalladation of β-allenylmalonates : a way to cyclopentenyl or vinylcyclopropyl derivatives.

The palladium-catalyzed addition of a vinyl or aryl halide to the enolate of β-allenyl malonate $\text{2}$ leads to the formation of either of the two cyclized products $\text{3}$ and $\text{4}$ depending mainly on the bulk of the starting unsaturated halide.     

The evaluation of a biogenetically based approach to the synthesis of octahydro-1h-benzofuro[3,2-e]isoquinolines

A potential synthetic route to octahydro-1$\text{H}$-benzofuro [3,2-e]isoquinoline derivatives by intermolecular oxidative phenolic coupling has been studied. A variety of successful coupling reactions have been effected between 2-naphthol or 4-t-butylphenol and p-cresol, 2-(p-hydroxyphenyl)ethanol, 3,4-dimethylphenol, 5-indanol and 6-hydroxytetralin, but 2-acetyl-7-hydroxytetrahydroisoquinoline failed to participate in such reactions.     

Un nouveau type d'alcaloïdes isoquinoleiques,les bisaporphines

The structures of Beccapoline and Beccapolinium, two new isoquinoline alkaloids from $\text{Polyathia beccarii}$, Annonaceae, have been elucidated by spectroscopic analysis. They are the first examples of natural bisaporphines.     

Synthesis of functionalised cyclopentanes by intramolecular radical-mediated cyclisations of terminal allenic ketones

Electrolysis of a series of terminal allenic ketones e.g. (7), (10), (17) and (21) is shown to result in intramolecular reductive cyclisation, through the $\text{exo}$-mode, producing five-membered rings, $\text{viz}$ (8), (9), (20) and (22) respectively, incorporating a bridgehead hydroxyl group. The unsaturated alcohols (8), (20) and (22), are also obtained when the allenic ketones (7), (17) and (21) are treated with sodium naphthalenide. By contrast treatment of (10) in the sodium naphthalenide gives a low yield ($\text{ca}$ 7%) of the isomeric indenol (11) by cyclisation through the $\text{endo}$-mode.Reductive cyclisations of the terminal acetylenic ketones (14) and (30) produce the corresponding unsaturated alcohols (26) and (31) respectively. Treatment of the alcohols (26) and (31) with catalytic selenium dioxide then provides the enediols (27) and (32) respectively, which make up the B/C ring systems of the novel marine natural products capnellenediol (1) and isoamijiol (2).     

On 1,3-beonzoxazepine and 3,1-benzoxazepine

The photochemistry of quinoline and isoquinoline $\text{N}$-oxides has been reexamined. 3, 1-Benzoxazepine, which had not been isolated as yet, was obtained from the former, while the formation of 1, 3-Benzoxazepine from the latter was demonstrated.     

Dienophilie des cyano-1 enamines,nouveaux equivalents de cetenes pour les cycloadditions de diels-alder1

The Diels-Alder reactivity of two captodative olefins, 2-morpho-lino-acrylonitrile $\text{15}$ and 2-(N-methlanilino) -acrylonitrile $\text{16}$, towards four conjugated dienes is evaluated.In every cases, isomeric {4+2} cyclo-adducts are obtained.With olefin $\text{15}$ yields are better than with olefin $\text{16}$. The adducts are easily transformed in to the corresponding ketones by a mild hydrolysis of the α-aminonitrile group. Thus, the 1-cyanoenamines can be considered as good ketene equivalents very useful for the synthesis of unsaturated cyclohexanones.     

Synthesis of bicyclo[6.2.2] bridgehead dienes

Bicyclo[6.2.2]dodecadienes ($\text{2}$), ($\text{3a}$), and ($\text{3b}$) having two bridgehead double bonds were synthesized by the pyrolysis of the acetate ($\text{1}$).     

Stereochemically controlled synthesis of unsaturated acids via diphenylphosphinoyl (Ph2PO) -ketoacids

Acylation of phosphine oxide anions with derivatives of cyclic anhydrides or oxidative cleavage of cyclic allyl phosphine oxides gives Ph₂PO-ketoacids: reduction, separation of diastereoisomers, and completion of the Horner-Wittig reaction gives single isomers ($\text{E}$) or ($\text{Z}$) of unsaturated acids.     

Phosphorus heterocycle synthesis by RPX2,· AlX3 addition to [1,n]dienes VII.

The RPX₂·AlX₃ complex ($\text{1}$) reacts with unsaturated ketones and imines to give novel 7-oxa and 7-aza-2-phosphabicyclo[2.2.1]heptanes (compounds $\text{3}$ and $\text{6}$ respectively).A new 1,3-dipolar addition of (CH₃)₂ CCH₂P?XR to nArN=C=S was disclosed resulting in the formation of the 2-imino-1,3-thiaphospholanes ($\text{7}$).     

13C NMR of carbonyl compounds. 3. Structure and dynamics of protonated enones and dienones

The unsaturated ketones $\text{1}$1 – $\text{10}$10 were protonated at low temperatures and studied by dynamic ¹³C NMR spectroscopy. Four interconverting stereoisomers were detected which differ in their conformation with respect to the CO and CC (enone) single bond.