256429-71-7

Upstream product

• 112968-75-9 (5R)-(L-menthyloxy)-2(5H)-furanone 
• 121-69-7 N,N-dimethyl-aniline 

Downstream Products

• 2216-51-5 (-)-menthol 

Relevant academic research and scientific papers

Origin of Chiral Induction in Radical Reactions with the Diastereoisomers (5R)- and (5S)-5-l-Menthyloxyfuran-2[5H]-one

Acetalization of 5-hydroxyfuran-2[5H]-one with l-menthol yields (5R)-(1) and (5S)-5-l-menthyloxyfuran-2[5H]-one (2) in equal amounts. The diastereomer 1 crystallizes preferentially. For the first time, the isolation of pure diastereoisomer 2 is reported. Different diastereoselectivities were observed in the radical tandem reaction of 1 and 2 with N,N-dimethylaniline. The privileged conformations in solution of the substrates and the products of the radical reaction were then determined, and X-ray crystal structure analyses were carried out on the reaction products. The different stereoselectivities in both cases are explained by different orientations of the menthyloxy substituent.

Diastereoselective radical tandem addition-cyclization reactions of aromatic tertiary amines by semiconductor-sensitized photochemical electron transfer

The diastereoselective radical tandem addition-cyclization reaction of N,N-dimethylaniline (2) with menthyloxyfuranone 1 was initiated by photochemically induced electron transfer using inorganic semiconductors (TiO2, ZnS, SiC and SnO2) as sensitizers. The rearomatization step, which also causes the partial reduction of 1, was studied by isotopic labeling experiments using deuterated derivatives of 2. The influence of the semiconductor surface on these processes has been characterized and compared with the results obtained under homogeneous conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Diastereoselective tandem addition-cyclization reactions of unsaturated tertiary amines initiated by photochemical electron transfer (PET)

Polycyclic molecules and tetrahydroquinoleines were obtained in a tandem reaction involving the diastereoselective addition of α-aminoalkyl radicals to (5R)-5-menthyloxy-2[5H]-furanone 1. The facial diastereoselectivity on 1 is ≥90%. The α-aminoalkyl radicals were produced from tertiary amines by photochemical-induced electron transfer. When N, N-dialkylanilines 19 were used as starting tertiary amines, a rearomatization step was involved and important side reactions of 1 were observed. A mechanistic study involving isotopic labeling of the starting amine indicated that the byproducts resulted from reduction of I during the rearomatization process. An efficient optimization of the reaction was obtained by simply adding acetone or cyclopentanone as mild oxidants to the reaction mixture. The side products resulting from reduction of the furanone 1 were completely suppressed under these conditions, and the yields of the tetrahydroquinolines 21ai, 22a-f, and 26g-i were doubled.

Stereoselective radical-tandem reaction of aniline derivatives with (5R)-5-menthyloxy-2,5-dihydrofuran-2-one initiated by photochemical induced electron transfer

The radical tandem reaction of simple alkyl derivatives of aniline to a chiral furanone can be carried out stereoselectively in high yields; the furanone is also involved as oxidant in a rearomatisation process (formation of byproducts) where it can be re