(1RS,3SR)-1-(4-Methylbenzyl)-7-phenyl-5-oxa-6-azaspiro[2.4]hept-6-en-4-one

Round 1

Reviewer 1 Report

I found the short note titled “(1RS,3SR)-1-(4-Methylbenzyl)-7-phenyl-5-oxa-6-azaspiro[2.4]hept-6-en-4-one by Titov and Rostovskii an interesting read. The paper essentially describes an unusual reaction of a benzylideneisoxazol-5-one with an excess diazomethane, which delivers two methylene groups. This is unusual because while the obtained compound is as expected a spirocyclic compound, the product is product contains an additional methylene group between the cyclopropane and the p-tolyl unit.

The paper is well composed. It points out that the established Corey-Chaykovsky is not suitable for reaction with the starting material. Using excess diazomethane instead, cyclopropanation can be accomplished and it is stated that several compounds are formed. Unfortunately, no further information is provided to the identity of the other compounds.

The title compound was obtained in 34 % yield, isolated by flash chromatography. Characterization of the compound includes ¹H, ¹³C NMR spectroscopy and the molecular structure eventually was established unambiguously by single crystal diffraction analysis.   

Minor things:

·         The expression “X-Ray” should be changed to “X-ray”

·         In the General Instrumentation section the 3 in ¹³C should be superscript.

·         In the prep of compound 3, change 0.9 mmol to 0.900 mol in order to provide the same number of significant digits for the molar concentration as for the amount.

·         On page 2 please reconsider the use of the expression “overwhelming”. “ ”surprising” or “unusual” might be good alternatives.

My overall assessment is that this is an interesting paper. A native English speaker should check on the use of articles. Once the mentioned things and a language check has been done, this fine paper might be published.

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Author Response

Please see the attachment

Author Response File: Author Response.pdf