Diastereoselective synthesis of tetrahydropyranes <i>via</i> Ag(<scp>i</scp>)-initiated dimerization of cinnamyl ethers
作者:Davide Ruggeri、Elena Motti、Nicola Della Ca’、Giovanni Maestri
DOI:10.1039/d2ob01876d
日期:——
We present herein the first synthesis of tetrahydropyranes promoted by a silver salt. Cinnamyl ethers undergo a formal dimerization affording the target heterocycle viasequential C–O bond cleavage/C–H bond functionalization. The cascade allows one to assemble three new bonds and to establish up to four stereocenters. The reaction likely proceeds through a cationic manifold that forms the target in
Electrohydrodynamically Enhanced Convective Boiling of Alternative Refrigerants: Fundamental Understanding and Applicability
作者:James Bryan、Jamal Seyed-Yagoobi
DOI:10.1080/10789669.2002.10391294
日期:2002.10.1
Electrohydrodynamically (EHD) enhanced convective boiling, based on the extraction phenomenon, is experimentally investigated. The working fluids are R-134a and R404A refrigerants. Both smooth and enhanced tubes are investigated in a horizontal configuration. The heat transfer enhancement and suppression with the corresponding pressure-drop data are presented. The ratio of EHD power consumption relative to the heat transferred was less than 1.5% for the data presented A theoretical analysis is presented to determine the contributing terms of the EHD power consumption, and it was determined that the electric conduction mechanism was the primary contributing factor to current flow. The transient application of EHD, in the case that resulted in the suppression of the heat transfer under steady-state conditions, provided transient enhancements for convective boiling of R-404A in a horizontal smooth tube. Additional, applicability of the EHD extraction phenomenon to convective boiling is discussed.
Sampath Kumar; Joyasawal, Sipak; Reddy, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2005, vol. 44, # 8, p. 1686 - 1692