Albrecht, Dominik; Vogt, Florian; Bach, Thorsten published an article in 2010, the title of the article was Diastereo- and Enantioselective Intramolecular [2+2] Photocycloaddition Reactions of 3-(ω’-Alkenyl)- and 3-(ω’-Alkenyloxy)-Substituted 5,6-Dihydro-1H-pyridin-2-ones.Electric Literature of 14602-86-9 And the article contains the following content:
3-(ω’-Alkenyl)-substituted 5,6-dihydro-1H-pyridin-2-ones I (n = 1-3) were prepared as photocycloaddition precursors either by cross-coupling from 3-iodo-5,6-dihydro-1H-pyridin-2-one or, more favorably, from the corresponding α-(ω’-alkenyl)-substituted δ-valerolactams by a selenylation/elimination sequence (56-62% overall yield). 3-(ω’-Alkenyloxy)-substituted 5,6-dihydro-1H-pyridin-2-ones II (n = 1, 2) were accessible in 43 and 37% overall yield from 3-diazopiperidin-2-one by an α,α-chloroselenylation reaction at the 3-position followed by nucleophilic displacement of a chloride ion with an ω-alkenolate and oxidative elimination of selenoxide. Upon irradiation at λ = 254 nm, the precursor compounds underwent a clean intramol. [2+2] photocycloaddition reaction. The substrates tethered by a two-atom chain exclusively delivered the resp. crossed products III (X = CH2, O), and the substrates tethered by longer chains, gave the straight products IV (n = 1, X = CH2, O; n = 2, X = CH2). The completely regio- and diastereoselective photocycloaddition reactions proceeded in 63-83% yield. Irradiation in the presence of the chiral templates (-)-V and (+)-VI at -75° in toluene rendered the reactions enantioselective with selectivities varying between 40 and 85% ee. Truncated template rac-VI was prepared as a noranalogue of the well-established template V in eight steps and 56% yield from the Kemp triacid. Subsequent resolution delivered the enantiomerically pure templates (-)-ent-VI and (+)-VI. The outcome of the reactions is compared to the results achieved with 4-substituted 5,6-dihydro-1H-pyridin-2-ones and quinolones. The experimental process involved the reaction of (1R,2S,5R)-2-Isopropyl-5-methylcyclohexyl carbonochloridate(cas: 14602-86-9).Electric Literature of 14602-86-9
The Article related to alkenyl substituted valerolactam selenylation elimination, dihydropyridinone alkenyl substituted derivative preparation photocycloaddition, piperidinone tricyclic derivative stereoselective preparation chiral complexing reagent, kemp triacid tetrahydroaminonaphthol chiral template preparation resolution and other aspects.Electric Literature of 14602-86-9
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