In this task, you will be given a passage to read. A fill in the blank question will be given to you. Your answer should fit the blank appropriately.

The reaction mechanism for the Johnson Corey Chaykovsky reaction consists of nucleophilic addition of the ylide to the carbonyl or imine group . A negative charge is transferred to the heteroatom and because the sulfonium cation is a good leaving group it gets expelled forming the ring . In the related Wittig reaction , the formation of the much stronger phosphorus @-@ oxygen double bond prevents oxirane formation and instead , olefination takes place through a 4 @-@ membered cyclic intermediate . The trans diastereoselectivity observed results from the reversibility of the initial addition , allowing equilibration to the favored anti betaine over the syn betaine . Initial addition of the ylide results in a betaine with adjacent charges ; density functional theory calculations have shown that the rate @-@ limiting step is rotation of the central bond into the conformer necessary for backside attack on the sulfonium . The degree of reversibility in the initial step ( and therefore the diastereoselectivity ) depends on four factors , with greater reversibility corresponding to higher selectivity : Stability of the substrate with higher stability leading to greater reversibility by favoring the starting material over the betaine . Stability of the ylide with higher stability similarly leading to greater reversibility . Steric hindrance in the betaine with greater hindrance leading to greater reversibility by disfavoring formation of the intermediate and slowing the rate @-@ limiting rotation of the central bond . Solvation of charges in the betaine by counterions such as lithium with greater solvation allowing more facile rotation in the betaine intermediate , lowering the amount of reversibility . fill in the blank : The reaction mechanism for the Johnson Corey Chaykovsky reaction consists of nucleophilic addition of the ylide to the carbonyl or __________________ group .
imine

Barker was born the second daughter and youngest child of Walter Barker , a partner in a seed supply company and an amateur artist , and his wife Mary Eleanor ( Oswald ) Barker on 28 June 1895 at home at 66 Waddon Road in Croydon , Surrey , England . Barker was an epileptic as a child , and cared for at home by her parents . Later , her sister and elder by two years , Dorothy Oswald Barker , continued the care . The family of four was moderately well off , and belonged to the lower end of the upper middle class . A nanny , a governess , and a cook to prepare special meals for Barker were hired . She spent much time in bed at home amusing herself with painting books and a nursery library that included the works of Kate Greenaway and Randolph Caldecott two artists who exerted strong influences on her later art.fill in the blank : Barker was born the second daughter and youngest child of Walter Barker , a partner in a seed supply company and an amateur artist , and his wife Mary __________________ ( Oswald ) Barker on 28 June 1895 at home at 66 Waddon Road in Croydon , Surrey , England .
Eleanor

The fruitbodies ( ascocarps ) of Geopyxis carbonaris are cup shaped , 1 2 cm wide , and have fringed whitish margins . The inner spore @-@ bearing surface of the cup , the hymenium , is brick red and smooth , while the exterior surface is a dull yellow , and may be either smooth or have blister @-@ like spots ( pustules ) . The stipe is small ( 1 1 @.@ 5 mm long and 1 2 mm wide ) , whitish in color , and expands abruptly into the cup . The brownish flesh of the fungus is thin and brittle . It does not have any distinctive taste , but has an unpleasant smell when crushed in water . The edibility of the fungus is not known , but the fruitbodies are insubstantial and unlikely to be harvested for eating .fill in the blank : The fruitbodies ( ascocarps ) of Geopyxis carbonaris are cup shaped , 1 __________________ cm wide , and have fringed whitish margins .
2