Visible-light-mediated flow protocol for Achmatowicz rearrangement

• Joachyutharayalu Oja,
• Sanjeev Kumar and
• Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

• platform developed with an integrated system enabling a downstream process in a time and labor-efficient manner which facilitates the Achmatowicz rearrangement, resulting in a fast (10 min) formation of the dihydropyranone products. Keywords: Achmatowicz reaction; flow chemistry; furfuryl alcohols

• -prefunctionalized materials in order to proceed with the rearrangement. However, the Achmatowicz reaction or similar methodologies involve a catalytic to stoichiometric amount of oxidants such as m-CPBA [7], PCC [8], Br2 [9], NBS [10], DMDO [11], KBr/Oxone [12], Na2S2O8 [13], photosensitizers/O21 [14], or Me2S [15

• ], spirulina [16], Ti(OiPr)4/t-BuOOH [17], VO(acac)2)/t-BuOOH [18], and enzymatic oxidation [19] etc., which may compromise the environmental benefits (Scheme 1a,b) and take longer reaction times. Alternatively, a new green pathway is necessary for the Achmatowicz reaction to be performed in a faster and safer

Recent applications of the divinylcyclopropane–cycloheptadiene rearrangement in organic synthesis

• Sebastian Krüger and
• Tanja Gaich

Beilstein J. Org. Chem. 2014, 10, 163–193, doi:10.3762/bjoc.10.14

• , see Scheme 22) [152], isolated from the leaves of Gelsemium elegans was accomplished by Fukuyama and coworkers [153][154]. Starting from furfuryl alcohol (179) an epoxide initiated Achmatowicz reaction [155] took place to give α,β-unsaturated pyrane 180. Next in line was an enzyme catalyzed dynamic

Directed aromatic functionalization in natural-product synthesis: Fredericamycin A, nothapodytine B, and topopyrones B and D

• Charles Dylan Turner and
• Marco A. Ciufolini

Beilstein J. Org. Chem. 2011, 7, 1475–1485, doi:10.3762/bjoc.7.171

• we describe as the “aza-Achmatowicz reaction” [47][48][49][50][51][52]: A transformation that has attracted the attention of a number of researchers worldwide [53][54][55][56][57][58][59][60][61][62]. In the course of such endeavors, we have often resorted to the facile C-2 deprotonation of furan as