10346-43-7Relevant articles and documents
Continuous-flow synthesis of vitamin D3
Fuse, Shinichiro,Tanabe, Nobutake,Yoshida, Masahito,Yoshida, Hayato,Doi, Takayuki,Takahashi, Takashi
, p. 8722 - 8724 (2010)
A highly efficient, two-stage, continuous-flow synthesis of vitamin D 3 from provitamin D3 was achieved. The developed method afforded the desired product in high yield (HPLC-UV: 60%, isolated: 32%) and required neither intermediate purification nor high-dilution conditions. The Royal Society of Chemistry 2010.
Novel Photosensitizers for the E/Z-Isomerization of Trienes. Part 1. Synthesis and Application
Pfoertner, Karl-Heinz
, p. 523 - 526 (2007/10/02)
Uranine and its thioxanthene and selenoxanthene analogues, as well as the disodium salts of o-(6-hydroxy-3-oxo-3H-xanthen-9-yl)benzenesulphonic acid and its thioxanthene and selenoxanthene analogues, show different photosensitizer properties in the E/Z-isomerization of trienes.This has been verified by applying them to the technically useful conversion of tachysterol into previtamin D.The synthesis of the novel photosensitizers with thioxanthene and selenoxanthene moieties are also described.
Determination of the Molar Absorptivity (ε) of the Photoisomers of 3β-Hydroxy-cholest-5,7-diene (Provitamin D3)
Gliesing, S.,Reichenbaecher, M.,Ilge, H.-D.,Fassler, D.
, p. 311 - 320 (2007/10/02)
A method is described which allows the determination of the molecular absorptivity (ε) of all components in a four-component system and is applied to the ε-determination of the photoisomers of provitamin D3 (1): praevitamin D3 (2), lumisterol3 (3), and tachysterol3 (4).By means of irradiation with appropriate wavelengths the four-component system is reduced to a two- and a three-component system, respectively, and the unknown molar absorptivities are evaluated numerically or graphically.
Bridged-ring steroids. III. The synthesis of bridged steroids with a bicycloheptane ring B system
Yates, Peter,Winnik, Francoise M.
, p. 2501 - 2506 (2007/10/02)
Reaction of cholesta-5,7-dien-3β-yl 2-tetrahydropyranyl ether with bromoform and potassium tert-butoxide gave 3',3'-dibromo-3',6β-dihydrocyclopropa-5a-cholest-7-en-3β-yl 2-tetrahydropyranyl ether (1c), which on treatment with lithium aluminium hydride and water gave 5,8α-methano-5α-cholest-6-en-3β-yl 2-tetrahydropyranyl ether (2c).This has been converted to 3β-acetoxy-5,8α-methano-5α-cholestan-6-one (16c) and 3β-acetoxy-5,8α-methano-5α-cholestan-7-one (17c).A preliminary investigation of the photochemistry of 16c and 17c has shown that the incorporation of the bicycloheptan-2-one system in the B ring of a steroid results in photoreactions of this system that are different from those observed in the case of simple bicycloheptan-2-ones.
