ETHYL CYCLOPROPYLPROPIOLATE

ALKYLIDENE/ARYLIDENE MALONATES IN ORGANIC SYNTHESIS SYNTHESIS OF ETHYL CYCLOPROPYLPROPIOLATE... 

ETHYL 4-CYCL0HEXYL-4-0X0BUTAN0ATE CYCLOHEXANEBUTANOIC ACID, Y-OXO-, ETHYL ESTER (54966-52-8), 65, 17 ETHYL CYCLOPROPYLPROPIOLATE, 66, 173, 174... 

ETHYL 4-CYCLOHEXYL-4-OXOBUTANOATE CYCLOHEXANEBUTANOIC ACID, Y-OXO-, ETHYL ESTER (54966-52-8), 65, 17 ETHYL CYCLOPROPYLPROPIOLATE, 66, 173,174 ETHYL (E,Z)-2,4-DECADIENOATE (3025-30-7), 66, 22, 23, 25, 28 Ethyl 3,4-decadienoate (36186-28-4), 66, 22, 28 Ethyl decanoate Decanoic acid, ethyl ester (110-38-3), 67,125 ETHYL DIETHOXYPROPANOATE PROPANOIC ACID, 3.3-DIETHOXY-,... 

Base-mediated (Formal) Cycloadditions. KHMDS, as well as other bases, have been used in the synthesis of pyrroles via a formal [3 + 2] cycloaddition of metalated isocyanides with ethyl cyclopropylpropiolate. The effect of the nature of the base on the ratio of the desired p3nrole product to the undesired ketone byproduct was investigated. The proposed mechanism consists of a formal cycloaddition of the metalated isocyanides across the triple bond, followed by a 1,5-hydrogen shift and protonation. The reaction between benzyl isocyanide and f-butyl cyclopropylpropiolate mediated by f-BuOK (2 h, rt) afforded a mixture of both the products in 96% combined yield and 1 1 ratio (eq 90). Similar results were achieved in reactions mediated by KHMDS both at rt and —78 °C (93% and 86% combined yields of 1 1 mixtures) (eq 90). The replacement of KHMDS with NaHMDS and LiHMDS led to a nearly exclusive formation of the undesired ketone product. The content of the undesired ketone product appeared to increase when harder cations were used. Accordingly, the application of t-BuOCs (2 h, rt) afforded 91% combined yield of the two products in a 96 4 ratio favoring the heterocycle (eq 90). 

Cyclopropylpropiolic acid ethyl ester, 66, 177 Davis reagent, 66, 203... 

Cyclopropylpropiol ic acid ethyl ester has the following spectra ... 

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