The first examples of transannular ring transformations in azirino-fused eight-membered O,N- or S,N-heterocycles involving selective aziridine ring opening and medium-sized ring contraction are described, which provide an access to functionalized 1,4-benzox(thi)azines or 1,3-benzox(thi)azoles.

An enantiocontrolled synthesis pathway has been developed to provide formation of tricyclic amine 7, representing the ABC ring system of the complex alkaloid daphnicyclidin A (1). Our efforts describe preparation of the Z-hexahydro-(1H)-azocine 29 and cyclization to construct the novel 4-azabicyclo[5.3.2]dodecane 31. Transannular reductive amination following the deprotection of 31 gave the des...

Objectives: To determine the immediate and early outcome of pulmonary valve cusp augmentation for repair tetralogy Fallot (TOF)
 Methods: A descriptive study 36 cases TOF done from July 2020 to December 2022 at Faisalabad Institute cardiology (FIC). Autologous pericardium used in all augment increase size orifice. Patients were followed post operative period by doing echocardiography obser...

Two hundred and nine patients underwent total repair of tetralogy of Fallot without congenital pulmonary atresia from 1971 to 1979. The age of the patients ranged from 22 months to 27 years (mean 6.8 years). Previous palliative shunts were present in 130 patients (62.2%). The right ventricular outflow tract obstruction was relieved by infundibulectomy in 31 patients (14.8%), by transannular pat...

An enantioseletive, biomimetic synthesis of (-)-longithorone A has been achieved using an intermolecular/transannular Diels-Alder sequence which provides some support for the proposed biosynthesis. The cycloaddition precursors were two [12]-paracyclophanes that were constructed with atropisomer control during ene-yne metathesis macrocyclizations.

Zethrene derivatives substituted by phenylethynyl groups bearing electron-donating and/or accepting groups were synthesised by iodine-induced transannular cyclisation of dehydrodinaphtho[10]annulene as the pivotal step followed by Sonogashira coupling reaction. Their physical properties were investigated to elucidate the effects of the substituents on the electronic configuration of the zethren...

The total synthesis and structural revision of antibiotic CJ-16,264 is described. Starting with citronellal, the quest for the target molecule featured a novel bis-transannular Diels-Alder reaction that casted stereoselectively the decalin system and included the synthesis of six isomers before demystification of its true structure.

Nucleophilic attack on seven-membered-ring oxocarbenium ions is generally highly stereoselective. The preferred mode of nucleophilic attack forms the product in a conformation that minimizes transannular interactions, thus leading to different stereoselectivity as compared to that of reactions involving six-membered-ring oxocarbenium ions.