Yu, Shuling published the artcileSynthesis of Cyclopentenones through Rhodium-Catalyzed C-H Annulation of Acrylic Acids with Formaldehyde and Malonates, Application In Synthesis of 638-45-9, the publication is Organic Letters (2021), 23(13), 5054-5059, database is CAplus and MEDLINE.
An efficient rhodium-catalyzed protocol for the synthesis of cyclopentenones I (R1 = Et, Bn, c-hexyl, etc.; R2 = H, Me, Et, Ph; -R1R2– = -(CH2)3-, -(CH2)4-; R3 = Me, Et, n-Pr, i-Pr, n-Bu) based on a three-component reaction of acrylic acids, formaldehyde, and malonates via vinylic C-H activation is reported. Exploratory studies showed that 5-alkylation of as-prepared cyclopentenones could be realized smoothly by the treatment of a variety of alkyl halides with a Na2CO3/MeOH solution Excess formaldehyde and malonate led to a multicomponent reaction that afforded the multisubstituted cyclopentenones II (R1 = n-Bu, 3-FC6H4, Ph(CH2)2, etc.; R2 = H, Me, Et, etc.; R3 = Me, Et, n-Pr, i-Pr; -R1R2– = -(CH2)4-) through a Michael addition
Organic Letters published new progress about 638-45-9. 638-45-9 belongs to iodides-buliding-blocks, auxiliary class Iodide,Aliphatic hydrocarbon chain, name is 1-Iodohexane, and the molecular formula is C7H10O4, Application In Synthesis of 638-45-9.
Referemce:
https://en.wikipedia.org/wiki/Iodide,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com