Write the structures of the initially formed enol tautomers in the reactions of propyne and dicyclohexylethyne with dicyclohexylborane followed by NaOH and H₂O₂ (Problems 44, part i, and 45, part i).

(a) D₂, Pd – CaCO₃, Pb(O₂CCH₃)₂, quinoline;

(b) Na, ND₃;

(c) 1 equivalent HI;

(d) 2 equivalents HI;

(e) 1 equivalent Br₂;

(f) 1 equivalent ICl;

(g) 2 equivalents ICl;

(h) H₂O, HgSO₄, H₂SO₄;

(i) dicyclohexylborane, then NaOH, H₂O₂.