+ problem 1 :
U can understand like the reaction react following Ae mechanism:
Br+--Br- attach CH=CH to form CHBr-CH+ and this cationic was stable by Oxgen
after that's the OH attach by intramolecular cyclization reaction. done
+problem 2 :
that's not very difficult. firstly, starting metarial is 1-methylcyclohexane, second, 1-bromo-1-methylcyclohexan, following, 1-methylcyclohex-1-ene, heptan-2,7-dion. done
P.3:
so easy, ====>1- butene , then , 1,2-dibromobutane, then== buta-1-ine and hexa-3-ine , then hexene-3, then hexa-3,4-diol. done