45 research outputs found
16α-Bromo-17β-hydroxy-5α-androstan-3β-yl acetate
The title compound, C21H33BrO3, an intermediate in the synthesis of the neuromuscular blocking agent rocuronium bromide, contains two independent molecules in the asymmetric unit, which have almost identical geometries: in both molecules, the steroidal rings A, B and C have slightly flattened chair conformations and ring D assumes a half-chair conformation. In the crystal, O—H⋯O hydrogen bonds and weak C—H⋯O and C—H⋯Br interactions help to establish the packing
ChemInform Abstract: ON STEROIDS. CCXXVII. SOLVOLYSIS OF 5,6(β-CYCLOPROPANO-5β-CHOLESTANE-3β,19-DIOL 3-ACETATE 19-P-TOLUENESULFONATE
ChemInform Abstract: ON STEROIDS PART 153. 5,7-CYCLOSTEROIDS PART 7. THE EPIMERIC 1,2-EPOXIDES OF THE 5,7BETA-CYCLOSTEROID SERIES
ChemInform Abstract: STEROIDS. CCLXI. THE SOLVOLYSES OF 3α- AND 3β-(P-TOLUENESULFONATES) OF 19-ACETOXY-5,6β-CYCLOPROPANO-5β-CHOLESTANE-3,19-DIOLS
Placas de concreto sob o efeito da radiação solar.
This article deals with solar radiation infl uence on temperature of top surface of bitumen sheet which incidence on adjacent bitumen sheet laps in regular roof area. One of the major effect infl uencing durability and lifespan of bitumen sheets on roof structures is solar radiation which loads
waterproofi ng layer cyclically and randomly with variation of temperature. UV radiation is although responsible for bitumen sheet aging.Este trabalho apresenta a infl uência da radiação solar na temperatura das superfícies de placas de concreto e sua incidência nos pecas de concreto adjacentes em uma coberta. Um dos maiores efeitos da radiação solar se refl ete na durabilidade e vida útil de placas de concreto em estruturas de coberta.
Embora protegidas com camadas de impermeabilização essas estruturas são submetidas aos efeitos cíclicos e aleatórios da variação da temperatura e ação radiação ultra-violeta