Ring transformations of 6H-cyclopropa(5a,6a)pyrazolo(1,5-a)pyrimidine. II. Reaction of 5a-acetyl-6a-carbethoxy-5a,6a-dihydro-6H-cyclopropa(5a,6a)pyrazolo(1,5-a)pyrimidine-3-carbonitriles with N-methylaniline.

9-Meth­oxy-6a,11a-dimethyl-6a,11a-dihydro-6H-1-benzofuro[3,2-c]chromen-3-ol from Dalbergia oliveri

The title compound, commonly known as (+)-(6aS,11aS)-medicarpin, C(16)H(14)O(4), was isolated from Dalbergia oliveri and displays a rigid mol-ecule consisting of four fused rings. The benzofuran system is inclined at an angle of 76.49 (2)° with respect to the chroman unit. The compound exists as a polymeric chain arising from inter-molecular O-H⋯O bonding.

3-Acetyl-2-fluoro-6H-benzo[c]chromen-6-one

The title compound, C15H9FO3, was obtained in a one-pot synthesis by Suzuki-Miyaura cross-coupling and nucleophilic substitution reaction of 4'-chloro-2',5'-di-fluoro-aceto-phenone with o-(meth-oxy-carbon-yl)phenyl-boronic acid. The asymmetric unit contains two crystallographically independent mol-ecules related by a non-crystallographic inversion centre. There are face-to-face stacking inter-a...

Structures of 6H-SiC Surfaces

We have systematically studied reconstructions of the 6H SiC(0001) and (0007) surface under both Si rich and C rich condition using field ion-scanning tunneling microscopy (FI-STM). The sample was cleaned by in situ Si beam etching at 900-1000 'C. The Si rich and C rich phases were produced by annealing the sample in a Si flm and C2HZ, respectively. On the (0001) surface, the as-cleaned surface...

Crystal structure of methyl 7-phenyl-6a,7,7a,8,9,10-hexa­hydro-6H,11aH-thio­chromeno[3,4-b]pyrrolizine-6a-­carbox­ylate

In the title compound, C22H23NO2S, the inner pyrrolidine ring (A) adopts an envelope conformation with the methine C atom opposite the fused C-N bond as the flap. The thio-pyran ring (C) has a half-chair conformation and its mean plane is inclined to the fused benzene ring by 1.74 (11)°, and by 60.52 (11)° to the mean plane of pyrrolidine ring A. In the outer pyrrolidine ring (B), the C atom op...

Electron-irradiation-induced deep levels in n-type 6H–SiC