(R/S)-Ethyl 2-Acetoxy-4-phenyl-4H-chromene-3-carboxylate
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
A figure clearly displaying the prepared compound along with its numbering should be prominently included in the article.
In general, the figures require more careful preparation. The settings and sizes are inconsistent, and there are overlaps between numbers and symbols within the chemical structures.
The wording in the first paragraph of the results section (lines 42-52) is unclear. It references both successful and unsuccessful previous results, but it is not explicit which specific outcomes are being addressed. Furthermore, the references cited at the end of this section lack clarity; it is unclear to which specific results or findings they pertain.
The preparation of the starting material, ethyl (4R,3R)-2-oxo-4-phenylchroman-3-carboxylate 4, should be detailed within the results section.
Please clarify the phrase: “The data on the preparation of substituted 3,4-dihydrocoumarins have characterized them as not very stable compounds” (line 88) and provide a reference if necessary.
The notation “substituents in the 3th and 4th positions” (lines 95, 101) is unconventional and should be revised.
Scheme 2 does not depict pseudo-equatorial positions as indicated (line 95).
There is no explanation provided for the "orbital model"; the authors should clarify and expand upon these statements.
It is recommended that the synthesis procedure be described with greater precision. Details regarding stirring, atmosphere, TLC eluent, Rf values, and whether the reaction reached completion after 48 hours should be included. The extraction process with dichloromethane should indicate the volume used and the number of extractions performed. Additionally, the approximate amount of ice used, the method for solvent removal, and particularly the chromatography conditions, should be clearly specified. Have the authors identified any by-products during the course of the reaction? If so, please provide details.
Supplementary Information
The IR spectrum is inverted and requires correction.
The HRMS data are unreadable and should be revised.
In the hydrogen spectrum, the multiplets are not clearly readable. The authors might consider displaying them on a larger scale or providing an expanded view.
Comments on the Quality of English Language
Included in the general report
Author Response
Dear Editor,
I am writing in response to the remarks, questions and comments given by the Reviewers on our manuscript entitled: “Ethyl 2-acetoxy-4-phenyl-4H-chromene-3-carboxylate”.
Thank you very much for the time spent on detailed analysis of our work and comments on the manuscript. We performed the suggested specific edits, some of the sentences were rewritten. Please find the detailed responses below and the corresponding corrections highlighted in track changes in the re-submitted files.
Here are our answers to the comments:
Reviewer:
Comment 1: A figure clearly displaying the prepared compound along with its numbering should be prominently included in the article.
In general, the figures require more careful preparation. The settings and sizes are inconsistent, and there are overlaps between numbers and symbols within the chemical structures.
Response 1: All the Schemes and Figures were carefully regarded and revised as could be seen in the modified file of the manuscript.
Comment 2: The wording in the first paragraph of the results section (lines 42-52) is unclear. It references both successful and unsuccessful previous results, but it is not explicit which specific outcomes are being addressed. Furthermore, the references cited at the end of this section lack clarity; it is unclear to which specific results or findings they pertain.
Response 2: Thank you very much for this comment. The first paragraph was revised and we hope not it is clearer for the reader.
Comment 3: The preparation of the starting material, ethyl (4R,3R)-2-oxo-4-phenylchroman-3-carboxylate 4, should be detailed within the results section.
Response 3: The compound ethyl (4R,3R)-2-oxo-4-phenylchroman-3-carboxylate was included in the Results part.
Comment 4: Please clarify the phrase: “The data on the preparation of substituted 3,4-dihydrocoumarins have characterized them as not very stable compounds” (line 88) and provide a reference if necessary.
Response 4: A reference was provided for more information.
Comment 5: The notation “substituents in the 3th and 4th positions” (lines 95, 101) is unconventional and should be revised.
Scheme 2 does not depict pseudo-equatorial positions as indicated (line 95).
Response 5: The corrections were done. Concerning the depiction of pseudo-equatorial positions of the substituents. In the main draft of the manuscript we decided that the Scheme is going to be more complicated if we illustrate the two enantiomers mentioned in lines 43-45. Thus, we represented the enantiomers together using the wavy bond.
Comment 6: There is no explanation provided for the "orbital model"; the authors should clarify and expand upon these statements.
Response 6: Thank you very much for this comment. The paragraph (lines 107-115) was revised.
Comment 7: It is recommended that the synthesis procedure be described with greater precision. Details regarding stirring, atmosphere, TLC eluent, Rf values, and whether the reaction reached completion after 48 hours should be included. The extraction process with dichloromethane should indicate the volume used and the number of extractions performed. Additionally, the approximate amount of ice used, the method for solvent removal, and particularly the chromatography conditions, should be clearly specified. Have the authors identified any by-products during the course of the reaction? If so, please provide details.
Response 7: The recommended corrections were done.
Comment 8: Supplementary Information
The IR spectrum is inverted and requires correction.
The HRMS data are unreadable and should be revised.
Response 8: We would like to be excused for HRMS data. They were not converted in the right pictures during the conversion of .docx to .pdf file. The IR spectrum was inverted.
Comment 9: In the hydrogen spectrum, the multiplets are not clearly readable. The authors might consider displaying them on a larger scale or providing an expanded view.
Response 9: A 1H NMR spectrum with expanded areas was provided.
I hope that we managed to answer the reviewer comments and to make the appropriate changes to the manuscript.
Kind regards,
Prof. Rositca Nikolova
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsMissing space between system and the (line 115)
