Butynedioic acid/ester,

Butynedioic acid, esters, see Acetylenic acids, esters But-2-yne, hexafluoro-cycloaddition to azides, 60, 37... 

Dimethyl acetylenedicarboxyl ate Acetylenedicarboxylic acid, dimethyl ester (8) 2-Butynedioic acid, dimethyl ester (9) (762-42-5)... 

Propargyl bromide 1-Propyne, 3-bromo- (8,9) (106-96-7) Dimethyl acetylenedicarboxylate Acetylenedicarboxylic acid, dimethyl ester (8) 2-Butynedioic acid, dimethyl ester (9) (762-42-5) l,2-Hexadien-5-yne (8,9) (33142-15-3)... 

ROMP of norbornadiene derivatives. Preliminary results have shown that treatment of cyclopentadiene with butynedioic acid gave norbornadiene diacid 8, which could be coupled to glycine methyl ester to give monomer 9 (Scheme 3). Compound 9 was found to undergo ROMP when treated with initiator 3, and gave a polymer with a narrow molecular weight distribution. However, the synthesis of this class of monomer was more difficult than the synthesis of norbornene derivatives, so it was not pursued further. 

Photolysis of n5 2,4-dimethylpentadien-l-yl manganese tricarbonyl [Mn(Tl5-2,4-Mc2C5H5)(CO)3] has been reported 59 to afford the THF adduct [Mn(T 5-2,4-Me2C5H5)(CO)2(THF)], which on reaction with butynedioic acid dimethyl ester and diphenylacetylene afforded respectively T 5-l,2-dimethoxycarbonyl-4,6-dimethylcyclohepta-2,4-dien-l-yl manganese tricarbonyl (39) and Ti5-4,6-dimethyl-l,2-diphenylcyclohepta-2,4-dien-l-yl manganese tricarbonyl (40) in formal [5 + 2] cycloaddition reactions. Propynoic acid methyl ester formed the 2 1 adduct T 5 2-i,3.dimethyl-6-methoxycarbonyl-6-( -2 -methoxycarbonylvinyl)-cyclohepta-2,4-dien-l-yl manganese dicarbonyl (41) which was characterised by X-ray diffraction. 

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