488787-32-2Relevant academic research and scientific papers
Synthesis of tetrahydrocannabinols based on an indirect 1,4-addition strategy
William, Anthony D.,Kobayashi, Yuichi
, p. 8771 - 8782 (2002)
The synthetic procedure presented for the preparation of the title compounds requires 1,4-addition of bulky cuprates to cyclohexenones and subsequent reaction with electrophiles. However, the enolates generated by BF3·OEt2-assistance suffer from lack of nucleophilicity. To circumvent this problem, we developed an indirect method consisting of the following three steps: (1) iodination of the cyclohexenones at the α position; (2) BF3·OEt2-assisted 1,4-addition of cuprates (Ar2Cu(CN)-Li2, Ar = aryl) followed by quenching the enolates with water; (3) reaction of the α-iodo-β-arylcylohexanones thus formed with EtMgBr to generate magnesium enolates. The enolates thus generated in this way showed a high reactivity toward ClP(O)(OEt)2 to furnish enol phosphates. The aforementioned procedure was also applied to a synthesis of optically active Δ9-tetrahydrocannabinol. In addition, a naphthalene analogue of the latter compound was also synthesized in a similar way.
Umpolung Strategy for Arene C?H Etherification Leading to Functionalized Chromanes Enabled by I(III) N-Ligated Hypervalent Iodine Reagents
Mikhael, Myriam,Guo, Wentao,Tantillo, Dean J.,Wengryniuk, Sarah E.
, p. 4867 - 4875 (2021/09/14)
The direct formation of aryl C?O bonds via the intramolecular dehydrogenative coupling of a C?H bond and a pendant alcohol represents a powerful synthetic transformation. Herein, we report a method for intramolecular arene C?H etherification via an umpoled alcohol cyclization mediated by an I(III) N-HVI reagent. This approach provides access to functionalized chromane scaffolds from primary, secondary and tertiary alcohols via a cascade cyclization-iodonium salt formation, the latter providing a versatile functional handle for downstream derivatization. Computational studies support initial formation of an umpoled O-intermediate via I(III) ligand exchange, followed by competitive direct and spirocyclization/1,2-shift pathways. (Figure presented.).
