1 Give the mechanism for the synthesis of tyrbostin from benzaldehyde. Show how the carbanion is generated from malononitrile (NCCH2CN) and stabilised (5 marks).

Show the reaction of the carbanion with the benzaldehyde (5 marks). Show how the

resulting alkoxide (O-) is protonated (5 marks). Show how the alkene bond is formed

(5 marks)

CN

ON

&

NCCH2CN

Piperidine

Aldehyde

Tyrphostin

ted Kingdom)

Focus

Three alkali metals in group 1 are a. calcium, strontium, barium b. boron, aluminum, gallium c. sodium, potassium, rubidium d. fluorine, iodine, chlorine

What are the major types of a chemical compound

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.