Novel Synthesis of Methylenecyclobutanols and 4-Methylenetetrahydrofurans from γ-Oxide Ylides
摘要:
The reaction of partial derivative-halo-gamma-oxide ylide, prepared from methylenetriphenylphosphorane and epichlorohydrin, with aldehydes afforded alkylidenecyclobutanols in moderate yields. The reaction initially proceeded through internal nucleophilic attack on partial derivative-carbon of this ylide. Another novel approach toward the synthesis of 4-methylenetetrahydrofurans was achieved by the reaction of gamma-oxide ylides with paraformaldehyde.
Photoinduced Alcoholic α‐C−H Bond Anti‐Markovnikov Addition to Vinylphosphonium Bromides Followed by Wittig Olefination: Two‐Step Protocol for α‐C−H Allylic Alkylation of Alcohols
作者:Masaki Yoshida、Masaya Sawamura、Yusuke Masuda
DOI:10.1002/cctc.202200744
日期:2022.9.20
Photocatalytic Synthesis: A two-step protocol for the α-allylic alkylation of alcohols consisting of photocatalytic anti-Markovnikov addition of the α-C−H bond of alcohols to vinylphosphonium bromides and subsequent Wittig olefination with aldehydes is reported. The protocol is marked by simplicity of the photoreaction system with a single catalyst and broad scope of alcohols, ranging from readily