Example Identify all possible structural and stereoisomers that can result from the addition polymerization of (a) butadiene (b) chloroprene HHHH HCI H H C-C=C C=C-C=C H H H (a) (b)

A tautometric keto (A) – enol(B) equilibrium may be formulated as follows    (A)                                 (B)               CH3 – COH ß-----------àCH2 – CHOH               Given the following bond energies:       C – H = 435kJ mol-1       C – C = 368 C==C = 610 C – O = 357 kJmol-1 C==O = 748 kJmol-1 O – H = 462 kJ mol-1 Calculate the enthalpy change in going from Keto form (A) to the enol form (B)

Identify the relationship between the following pair of structures by describing them as represting enantiomers, diastereomers, constitutional isomers or two molecules of the same compounds (a) (c) H CH3 Br. CH3 Br f-f and Filmas H H CH3 H F Oll H CHO Br X-X ²=-= -OH HO and and H Br H- F C(O)CH, H (b) CH3 (d) H- and HO CHO -H -OH C(O)CH3

a (+)-9,10-deoxytridachione (a) What orbitals are used to form the indicated bond in a? (b) What is the geometry of the indicated O atom in b? (c) What is the indicated bond angle in c? (d) Which hybrid orbitals do the lone pairs on the Oxygen in d resides? (a) (b) (c) (d) **** (e)