(R)-4-Acetyl-10-(2-chloro-1,3-thiazol-4-yl)-5,11,13-trihydroxy-2,12-dimethyl-8-oxatricyclo[7.4.0.0^2,7]trideca-1(13),4,6,9,11-pentaen-3-one

Round 1

Reviewer 1 Report

Authors claim synthesis of (R)-4-acetyl-10-(2-chloro-1,3-thiazol-4-yl)-5,11,13-trihydroxy-2,12-dimethyl-8-oxatricyclo[7.4.0.0²,⁷]trideca-1(13),4,6,9,11-pentaen-3-one.

1) Many readers would like to know chemical yields for from "1 to 2 and 2 to 3" in scheme 1, and from "2 to 4 and 4 to 5" in scheme 2.

2) It is very difficult  to read reference 12 to reproduce synthesis 2 and 4. Reviewer recommended the details of protocol and chemical yields will be cited in supporting information.

3) Please provide actual weight in experimental section. 

4) Reviewer can not recognize the description for "Figure 1. HMBS and HSQS data for compound 5 and the traditional numeration for usnic acid derivative"

5) Authors must describe the purity of the title compound by HPLC in the text body.

6) Is it essential "Scheme 3. Proposed mechanism of 2-chlorothiazole formation" in the text? Less data for the mechanism from authors' experiment or consideration for byproducts  or chemical yields (64%)

Author Response

Dear Reviewer, 

Thank you for paying attention to our article and sharing your helpful comments.

Comment 1: Many readers would like to know chemical yields for from "1 to 2 and 2 to 3" in scheme 1, and from "2 to 4 and 4 to 5" in scheme 2.

Response 1: Chemical yields was added to schemes 1 and 2.

Comment 2: It is very difficult to read reference 12 to reproduce synthesis 2 and 4. Reviewer recommended the details of protocol and chemical yields will be cited in supporting information.

Response 2: Detailed information about synthesis of compounds 2 and 4 have been added to supplementary materials.

Comment 3: Please provide actual weight in experimental section. 

Response 3: Actual weight of compound 4 introduced into the reaction is indicated in experimental section. We have added actual weight of product 5 and all compounds mentioned in synthesis of compounds 2 and 4

Comment 4: Reviewer cannot recognize the description for "Figure 1. HMBS and HSQS data for compound 5 and the traditional numeration for usnic acid derivative"

Response 4: There was a mistake. We changed HMBS and HSQS to HMBC and HSQC. We have also added detailed description for Figure 1.

Comment 5: Authors must describe the purity of the title compound by HPLC in the text body.

Response 5: The purity of compound 5 has been added in the text body.

Comment 6: Is it essential "Scheme 3. Proposed mechanism of 2-chlorothiazole formation" in the text? Less data for the mechanism from authors' experiment or consideration for byproducts or chemical yields (64%)

Response 6: No, it is no so essential. The reaction is quite well-known. We've removed scheme 3 and most of the discussion of the mechanism. We added some explanation about the chemical yield.

Round 2

Reviewer 1 Report

The manuscript is revised based on the reviewer's comments.