Highly efficient [2 + 2] intramolecular cyclizations of allenynes under microwave irradiation: construction of fused bicyclic compounds was written by Oh, Chang Ho;Gupta, Arun Kumar;Park, Dai In;Kim, Nakjoong. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2005.Quality Control of Diethyl 2-(prop-2-yn-1-yl)malonate This article mentions the following:
A palladium [2 + 2] cycloaddition of 1,6- and 1,7- allenyne carboxylates and microwave-mediated [2 + 2] cycloaddition of various 1,n-allenynes were developed and, particularly, the microwave irradiated [2 + 2] cycloaddition of allenynes can provide a simple, general and eco-friendly synthetic method to fused bicyclo[m,2,0]alkadienes. E.g., microwave irradiation of allenyne CH2:C:CHCH2N(Ts)CH2CCCO2Et gave 89% bicyclo[m,2,0]alkadiene I. In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Quality Control of Diethyl 2-(prop-2-yn-1-yl)malonate).
Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Quality Control of Diethyl 2-(prop-2-yn-1-yl)malonate
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics