Short synthesis of 6-oxoprostaglandin E1 and 6-oxoprostaglandin F1α

6-Oxoprostaglandin E₁ methyl ester was synthesized in a single pot from ($\text{R}$)-4-$\text{t}$-butyldimethylsiloxy-2-cyclopentenone by organocopper conjugate addition with an ω side-chain unit, trapping of the resulting enolate with 6-methoxycarbonyl-2-nitrohex-1-ene, and treatment with aqueous titanium(III) trichloride. Hydrolysis of the methyl ester was accomplished by porcine liver esterase. 6-Oxoprostaglandin F_1α, was obtained from 6-nitroprostaglandin E₁ methyl ester in four steps.     

Acid-catalysed reactions of 3,5-dialkyl-spiro[2.5]Octa-2,5-dien-4-ones

Acid-catalysed ring opening of the spirodienones ($\text{2a}$) and ($\text{2b}$) using p-toluene-sulphonic acid affords the styrène derivatives ($\text{3a}$) and ($\text{3b}$), while treatment with acetic anhydride/H₂SO₄ affords the furan derivatives ($\text{4a}$) and ($\text{4b}$).     

Adenosine cyclic 3′,5′-(RP)- and (SP)-phosphoramidates,the first representatives of nucleoside cyclic 3′,5′-phosphoramidates derived from ammonia

Adenosine cyclic 3′,5′-phosphoramidate $\text{2}$ was synthesized by reacting adenosine cyclic 3′,5′-phosphate $\text{1}$ with POCl₃, in trimethyl phosphate for 1 h at O°C, followed by in situ treatment of the reaction mixture with a suspension of (NH₄)₂CO₃ in anhydrous DMF or pyridine or DMF/pyridine mixture for 30 min at 25° C. Diastereoisomers ($\text{R}$_P)-$\text{2}$ and ($\text{S}$_P)-$\text{2}$ the relative quantities of which depended on the solvent of (NH₄)₂CO₃ treatment, were separated by reversed phase partition chromatography. Hydrolysis of (R_P)-$\text{2}$ and (S_P)-$\text{2}$ proceeded with predominant (90% in 0.1 N HCl, 100% in 0.1 N NaOH) -P-O-C bond breaking.     

Perfluoroalkyl derivatives of nitrogen. Part LI [1]. Reaction of the N-halogenobistrifluoromethylamines (CF3)2NX (X=Cl,Br) with norbornadiene

Reaction of the amines (CF₃)₂NX (X=Cl,Br) with norbornadiene either in solvent (CH₂Cl₂) at ?78 °C in the dark or in the vapour phase at 20 °C in daylight gives a mixture of 3-halogeno-5-($\text{NN}$-bistrifluoromethylamino)nortricyclene ($\text{exo}$, $\text{endo}$-and $\text{exo}$, $\text{exo}$-isomers) and $\text{exo}$-5-($\text{NN}$-bistrifluoromethylamino)- $\text{anti}$-7-halogenonorbornene in quantitative yield formed $\text{via}$ halonium ion addition to the diene. The reaction of the amine (CF₃)₂NBr in solvent Me₂O or Et₂O at ?78 °C in the dark gives the same products in low yield, together with 3-bromo-5-alkoxynortricyclene ($\text{exo}$, $\text{endo}$- and $\text{exo}$, $\text{exo}$-isomers) and the amine (CF₃)₂NR (R=Me, Et) in high yield.     

Cis-trihetero-tris-σ-homobenzenes as tridentate ligands - X-ray crystal. Structure analyses of the Co(C6H9N3)2(NO3)3 and Ba(C6H6O3)4(ClO4)2-complexes

According to X-ray crystal structure analyses “cis-benzenetrisimine” ($\text{2}$) and “cis-benzenetrioxide” ($\text{1}$) act as tridentate ligands in their 2:1- and 4:1-complexes $\text{7}$ (Co(C₆H₉N₃)₂(NO₃)₃) and $\text{8}$ (Ba(C₆H₆O₃)₄(ClO₄)₂), resp. The latter is the rare example of an organic complex with the (approximate) T-symmetry.     

Side-bonded ketone complexes of platinum(0). Alloxan and diethyl oxomalonate complexes and reactions of platinum(0) complexes with isatin and benzoyl cyanide.

Reactions of alloxan (all) with [PtL(PPh₃)₂] (L′= $\text{trans}$-stilbene, L″ diphenylacetylene) afford the side-bonded ketone complex [Pt(all)(PPh₃)₂] which may also be obtained from the hydrate of alloxan and [PtL′(Pph₃)₂]. Similarly diethyl oxomalonate (dio) and [Pt(PPh₃)₄] afford a side-bonded ketone complex [Pt(dio)(PPh₃)₂]. Reaction of isatin with [Pt(PPh₃₄] gives $\text{trans}$-[PtH{$\text{NCO(}\text{o}\text{-C}{}_6\text{H}{}_4\text{)CO}$}(PPh₃)₂] and benzoyl cyanide and [PtL′(PPh₃)₂] give $\text{cis}$-[Pt(CN)(COPh₃)₂] and $\text{trans}$-[Pt(CN)₂(PPh₂)₂].     

Stereospecific 2-vinylcyclohexanol formation via internal attack of an allylsilane moiety on an aldehyde group

Acid catalyzed cyclization of ($\text{E}$)-HCO-(CH₂)-₄-CH=C(Me)-CH(SPh)SiMe₃ affords $\text{cis}$-2-substituted cyclohexanol, while ($\text{Z}$) compound affords the $\text{trans}$ isomer. Those cyclized products are transformed to the corresponding α-methyl γ-lactones.     

Stereospecific synthesis of (5E)-PGE2 by palladium-catalyzed decarboxylative 2-alkenylation of 2-alkenyloxycarbonylated cyclopentanone derivative

(5$\text{E}$)-Prostaglandin E₂ methyl ester was synthesized from ($\text{R}$)-4-$\text{t}$-butyldimethylsiloxy-2-cyclopentenone by $\text{in}$$\text{situ}$ 2-alkenyloxycarbonylation of the organocopper conjugate-addition adduct followed by intramolecular palladium-catalyzed decarboxylative 2-alkenylation. A ($\text{E}$)-2-butenylated cyclopentanone derivative was obtained from either 2-[($\text{E}$)- or ($\text{Z}$)-2-butenyloxy-carbonyl]cyclopentanone derivative under the similar reaction condition.     

The oxidation of the benzotropylium cation

Oxidation of benzotropylium ($\text{1}$) fluoborate with Na₂O₂ and KO₂ gives the benzotropones, $\text{5}$ and $\text{6}$, as the major products with no naphthalene ($\text{9}$) or other ring contracted products formed. Oxidation with $\text{m}$-chloroperoxybenzoic acid produces a small amount of naphthaldehydes ($\text{10}$ and $\text{11}$) and even less naphthalene, a long with the benzotropones, while oxidation with H₂O₂ and $\text{t}$-butyl peroxyacetate gives slightly more of the ring contracted naphthaldehydes than benzotropones, in addition to a small quantity of naphthalene. All reactions produce some 1,2-benzotropilidene ($\text{8}$)     

Solid solution formation in chalcopyrite systems of the type AgInX2AgMIIIX2 where M = Al,Ga, and X = S,Se

Previous (1) work on ternary chalcopyrite solid solution formation has shown that the difference in end point axial ratios ($\text{Δc}\text{a}$) is an important factor in determining the extent of mutual solubility. It was concluded that when $\text{Δc}\text{a}\text{> 0.13}$ complete solid solubility will not occur. In this work it is shown that complete solid solution formation in the systems AgAlS₂AgInS₂ ($\text{Δc}\text{a}\text{= 0.111}$), AgGaS₂AgInS₂ ($\text{Δc}\text{a}\text{= 0.11}$) and AgAlSe₂AgInSe₂ ($\text{Δc}\text{a}\text{= 0.112}$) does occur. This shows that the value of $\text{Δc}\text{a}\text{= 0.13}$ as an upper limit for solid solution formation can be approached closely.     

The synthesis of a cationic ylide complex of platinum(II) by the reaction of tetrakis(triphenylphosphine)platinum(O) with choloroiodomethane.

The reaction of Pt(PPh₃)₄ with CH₂Cl1 in benzene yields the cationic ylide complex $\text{cis}$-[Pt(PPh₃)₂(CH₂PPh₃)Cl]I in high yield. This complex has been converted to $\text{cis}$-[(PPh₃)₂(CH₂PPh₃)X]X (X  Br or I) by reaction with LiBr or NaI. Reaction of $\text{cis}$-[Pt(PPH₃)I]I with iodine yields $\text{cis}$-[Pt(PPh₃)₂(CH₂PPh₃)I]I₃. Nmr data are given in support of the suggested structures.     

A new pathway in the reactions of chromones and hydroxylamine in anhydrous solutions

In the nucleophilic reaction of chromone ($\text{1}$) with NH₂OH·HC1 in anhydrous methanol a new compound 2-methoxychromanone ($\text{6}$) appeared as an intermediate in the formation of chromone oxime ($\text{8}$) and 2-methoxychromanone oxine ($\text{7}$).     

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 ($\text{12}$)     

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 ($\text{7}$).     

Optical resolution of tricarbonyl(1-carboxycyclohexa-1,3-diene) iron and the absolute configuration of the products

Resolution of the acid ($\text{1}$) (shown as the (+)-isomer) into its optically pure (+) and (?) isomers and reduction of the CO₂H yields the 2-Me derivative ($\text{2}$) (shown as the (?)-isomer). The absolute configuration of ($\text{2}$) is defined by conversion of the salt ($\text{3}$) of known configuration into ($\text{2}$) and ($\text{4}$). This is the first resolution leading to preparation of pure complexes of known absolute configuration.     

From penicillin to penem and carbapenem. VI1) : Synthesis of dethiathienamycin

A new C₃-unit substitution reaction at C-4 position of 4- acetoxyazetidinone derivative ($\text{1}$ and $\text{5}$) by tetraallyltin ($\text{2}$) in the presence of 1/10 eq. of BF₃-ether in methylene chloride is described. From 4-allylazetidinone derivative ($\text{3}$) via ylid intermediate ($\text{14}$) dethiathienamycin ($\text{16}$) was synthesized.     

The interaction of an osmium-carbon triple bond with copper(I), silver(I) and gold(I) to give mixed dimetallocyclopropene species and the structures of Os(AgCl) (CR) Cl(CO) (PPh3)2

The osmium carbyne complex, Os(CR)Cl(CO)(PPh₃)₂, (R  p-tolyl) reacts with Group I halides to form the mixed dimetallocyclopropene species, $\text{Os(Cul)(C}$R)Cl(CO)(PPh₃)₂, $\text{Os(AgCl)(C}$R)Cl(CO)(PPh₃)₂, $\text{Os(AuCl)(C}$R)Cl(CO)(PPh₃)₂, and [$\text{Os[Ag(OClO}{}_3\text{)](C}$R)Cl(CO)(MeCN)(PPh₃)₂] ClO₄ X-ray crystal structure determination of $\text{Os(AgCl)(C}$R)Cl(CO)(PPh₃)₂ confirms the presence of a three-membered ring and the structure can be viewed as the “acetylene-like” interaction of an osmium—carbon triple bond with AgCl. In acid solution AgCl is precipitated and an alkylidene complex results from proton addition to the carbyne ligand.     

A general synthesis of primary prostaglandins

Combination of ($\text{R}$)-4-$\text{t}$-butyldimethylsiloxy-2-cyclopentenone, ($\text{S}$)-($\text{E}$)-3-$\text{t}$-butyldimethylsiloxy-1-iodo-1-octene, and 6-methoxycarbonyl-2-hexynal via the tandem organo-copper conjugate addition—aldol reaction procedure leads directly to a 5,6-dehydroprostaglandin E₂ derivative, which can be transformed to a variety of chiral primary prostaglandins in a stereoselective manner.     

Temperature dependence of collisional deactivation of Tl(62P32)

The rate coefficients for the collisional deactivation of Tl(6²P_{$\text{3}\text{2}$}) by several gases has been determined at 300°K. This data is compared with that previously obtained at higher temperatures and the Arrhenius parameters calculated. Both the overall rate coefficients and temperature effects display trends similar to those observed for 1(5²P_{$\text{1}\text{2}$}) relaxation. The deactivation of Tl(6²P_{$\text{3}\text{2}$}) by O₂ is shown to proceed by a process involving an equilibrium with Tl(6²P_{$\text{1}\text{2}$}) and electronically excited oxygen, probably O₂(¹Δ_g).     

The importance of spin relaxation in the delayed fluorescence of molecular crystals

Deactivation rate constants of spin-orbital excited Br atoms in the reactions Br(²P_{$\text{1}\text{2}$}) + O₂ → Br(²P_{$\text{3}\text{2}$}) + O₂ (k₁), and Br(²P_{$\text{1}\text{2}$}) + NO → Br(²P_{$\text{3}\text{2}$}) + NO (k₄) have been measured with a photodissociative IBr laser on the electronic transition ²P_{$\text{1}\text{2}$}?²P_{$\text{3}\text{2}$} in the Br atom (λ = 2.7 μm). The values obtained are (6.4 ± 1.8) × 10^?14 cm³ s^?1 and (1.9 ± 0.6) × 10^?12 cm³ s^?1, respectively. Comparison with published data leads to the conclusion that, contrary to a widely accepted point of view, the high rate constants for the quenching of excited halogen atoms are due to resonant energy transfer processes and not to the paramagnetic nature of the quencher.