Highly diastereoselective addition of photochemically generated radicals to (5R)-(−)-menthyloxy-2[5H]-furanone - synthesis of(−)-terebic acid
摘要:
Photochemically generated ketyl and 2-dioxdanyl radicals are added with high diastereoselectivity (de > 95%) to (5R)-(-)-5-menthyloxy-2[5H]furanone. This reaction is used for the asymmetric synthesis of (-)-terebic acid. The double bond is attacked by the radicals on the ul-side.
Stereospecific radical addition of isopropanol andn-butanal to (5R)-(l-menthyloxy)furan-2(5H)-one
作者:Yu. N. Belokon'、K. A. Kochetkov、M. A. Moskalenko、N. I. Raevsky、T. F. Savel'eva、V. I. Tararov、T. D. Churkina
DOI:10.1007/bf00702401
日期:1995.3
The radicaladdition of PriOH andn-butanal to (5R)-5-(l-menthyloxy)furan-2(5H)-one occurs regio- and diastereospecifically at position 4 of the furanone ring.
A novel continuous-flow photoreactor with parallel capillaries was constructed and successfully tested for the DMBP-sensitized addition of isopropanol to furanones. Complete conversions were achieved after a maximum of 10 min of irradiation with a single 350 nm lamp. The results were compared to analogous batch experiments using a conventional Rayonet chamber reactor equipped with 16 UVA lamps. The capillary tower generally showed higher space-time yields. (C) 2010 Elsevier Ltd. All rights reserved.
Stereoselective intermolecular addition of ketyl radicals generated from ketones by photoinduced electron transfer
作者:Cédric Brulé、Norbert Hoffmann
DOI:10.1016/s0040-4039(01)02089-5
日期:2002.1
Ketyl radicals were produced from ketones by photochemical electron transfer and subsequent proton transfer from tertiary amines. These radicals were stereoselectively added to (5R)-5-(-)-menthyloxy-2[5H]-furanone 1. Due to their low reactivity, the alpha -aminoalkyl radicals which were generated at the same time were not added to 1. The ketones were used in stoichiometric quantities. (C) 2001 Elsevier Science Ltd. All rights reserved.
Parallel Microflow Photochemistry: Process Optimization, Scale-up, and Library Synthesis
A novel, multimicrocapillary flow reactor (M mu CFR) was constructed and applied to a series of sensitized photoadditions involving 2(5H)-furanones. The reactor allowed for rapid and energy-, time-, and space-efficient sensitizer screening, process optimization, validation, scale-up, and library synthesis.
Highly diastereoselective addition of photochemically generated radicals to (5R)-(−)-menthyloxy-2[5H]-furanone - synthesis of(−)-terebic acid
作者:Norbert Hoffmann
DOI:10.1016/s0957-4166(00)86239-4
日期:1994.5
Photochemically generated ketyl and 2-dioxdanyl radicals are added with high diastereoselectivity (de > 95%) to (5R)-(-)-5-menthyloxy-2[5H]furanone. This reaction is used for the asymmetric synthesis of (-)-terebic acid. The double bond is attacked by the radicals on the ul-side.