1-Methyl-2,4-bis­(2-methoxy­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

The crystal structure of the title compound, C23H27NO3, shows that the compound exists in a chair–chair conformation with an equatorial disposition of 2-methoxy­phenyl groups at an angle of 39.94 (3)° with respect to each other. An inter­molecular N—H⋯π inter­action is observed in the crystal packing

2,4-Bis(2-methyl­phen­yl)-3-aza­bicyclo[3.3.1]nonan-9-one O-methyl­oxime

The mol­ecule of the title compound, C23H28N2O, exists in a twin-chair conformation, with equatorial orientation of the ortho-tolyl groups on both sides of the secondary amino group. The title oxime compound and its ketone precursor 2,4-bis­(2-methyl­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one exhibit similar stereochemistries, with the orientation of the o-tolyl rings almost identical in both compounds. In the title compound, the tolyl rings are at an angle of 23.77 (3)° with respect to one another; the angle in the precursor is 29.4 (1)° [Vijayalakshmi, Parthasarathi, Venkatraj & Jeyaraman (2000 ▶), Acta Cryst. C56, 1240–1241]. The cyclo­hexane ring and the oxime ether are disordered over two alternative orientations, with a refined site-occupancy ratio of 0.813 (2):0.186 (4). The crystal structure of the title compound is stabilized by inter­molecular N—H⋯π inter­actions

2,4-Bis(4-propoxyphen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

In the title compound, C26H33NO3, a crystallographic mirror plane bis­ects the mol­ecule (two C atoms, one O atom and one N atom lie on the mirror plane). The mol­ecule exists in a twin-chair conformation with equatorial orientations of the 4-propoxyphenyl groups. The dihedral angle between the 4-propoxyphenyl groups is 31.58 (3)°

2,4-Bis(4-fluoro­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one

In the title compound, C20H19F2NO, a crystallographic mirror plane bis­ects the mol­ecule, passing through the N, O and two C atoms of the central ring system. The mol­ecule exists in a twin-chair conformation with equatorial dispositions of the 4-fluoro­phenyl groups on both sides of the secondary amino groups; the dihedral angle between the aromatic ring planes is 28.67 (3)°

Ethyl 4-hydr­oxy-2,6-diphenyl-1-(2-thio­morpholinopropano­yl)-1,2,5,6-tetra­hydro­pyridine-3-carboxyl­ate

In the title compound, C27H32N2O4S, the thio­morpholine ring adopts a chair conformation and the tetra­hydro­pyridine ring is in a distorted envelope conformation. The mol­ecular structure is stabilized by an intra­molecular O—H⋯O inter­action and the crystal packing is stabilized by an inter­molecular C—H⋯O inter­action, generating an S(6) motif and a dimer of the type R 2 2(18), respectively

Optimal set of grid size and angular increment for practical dose calculation using the dynamic conformal arc technique: a systematic evaluation of the dosimetric effects in lung stereotactic body radiation therapy

Purpose To recommend the optimal plan parameter set of grid size and angular increment for dose calculations in treatment planning for lung stereotactic body radiation therapy (SBRT) using dynamic conformal arc therapy (DCAT) considering both accuracy and computational efficiency. Materials and methods Dose variations with varying grid sizes (2, 3, and 4 mm) and angular increments (2°, 4°, 6°, and 10°) were analyzed in a thorax phantom for 3 spherical target volumes and in 9 patient cases. A 2-mm grid size and 2° angular increment are assumed sufficient to serve as reference values. The dosimetric effect was evaluated using dose–volume histograms, monitor units (MUs), and dose to organs at risk (OARs) for a definite volume corresponding to the dose–volume constraint in lung SBRT. The times required for dose calculations using each parameter set were compared for clinical practicality. Results Larger grid sizes caused a dose increase to the structures and required higher MUs to achieve the target coverage. The discrete beam arrangements at each angular increment led to over- and under-estimated OARs doses due to the undulating dose distribution. When a 2° angular increment was used in both studies, a 4-mm grid size changed the dose variation by up to 3–4% (50 cGy) for the heart and the spinal cord, while a 3-mm grid size produced a dose difference of \u3c1% (12 cGy) in all tested OARs. When a 3-mm grid size was employed, angular increments of 6° and 10° caused maximum dose variations of 3% (23 cGy) and 10% (61 cGy) in the spinal cord, respectively, while a 4° increment resulted in a dose difference of \u3c1% (8 cGy) in all cases except for that of one patient. The 3-mm grid size and 4° angular increment enabled a 78% savings in computation time without making any critical sacrifices to dose accuracy. Conclusions A parameter set with a 3-mm grid size and a 4° angular increment is found to be appropriate for predicting patient dose distributions with a dose difference below 1% while reducing the computation time by more than half for lung SBRT using DCAT

Ethyl 4-hydr­oxy-1-(2-morpholinopro­pano­yl)-2,6-diphenyl-1,2,5,6-tetra­hydro­pyridin-3-carboxyl­ate

In the title compound, C27H32N2O5, the morpholine ring adopts a chair conformation with two C atoms deviating by −0.656 (4) and 0.679 (3) Å from the least-squares plane defined by the rest of atoms in the ring. The tetra­hydro­pyridine ring adopts a half-chair conformation. The mol­ecular structure is stabilized by a strong intra­molecular O—H⋯O inter­action, generating an S(6) motif. The crystal packing is stabilized by inter­molecular C—H⋯O inter­actions, generating a C(7) chain along the a axis, and R 2 2(20) and R 4 4(20) graph-set motifs

2,4-Bis(2-methoxy­phenyl)-3-aza­bicyclo­[3.3.1]nonan-9-one

In the title compound, C22H25NO3, the mol­ecule has a pseudo-mirror plane. The structure is a positional isomer of 2,4-bis(4-methoxy­phenyl)-3-aza­bicyclo­[3.3.1]nonan-9-one [Cox, McCabe, Milne & Sim (1985 ▶). J. Chem. Soc. Chem. Commun. pp. 626–628]. The 3-aza­bicyclo­[3.3.1]nonan-9-one moiety adopts a double chair conformation with equatorial orientations of both 2-methoxy­phenyl substituents on either side of the secondary amino group. The benzene rings are oriented at an angle of 33.86 (4)° with respect to each other and the meth­oxy groups point towards the carbonyl group. The crystal structure is stabilized by intermolecular N—H⋯π inter­actions

1-Chloro­acetyl-2,6-bis­(2-methoxy­phen­yl)-3,5-dimethyl­piperidin-4-one

The piperidone ring in the title compound, C23H26ClNO4, adopts a boat conformation with its two out-of-plane C atoms deviating by 0.597 (2) and 0.630 (2) Å from the least-squares plane of the rest of atoms in the ring. The two aromatic rings are roughly perpendicular to each other, making a dihedral angle of 75.1 (1)°, and a C—H⋯π intra­molecular inter­action is observed. The crystal packing is stabilized by a C—H⋯O inter­molecular inter­action, generating a chain with a C(9) motif along the a axis