( Alkenes ( ( ( react ( with ( ( NBS and ) water ) ) ) ( in ( halohydrin ( formation reaction ) ) ) ) . ) )
(ROOT (S (NP (NNS Alkenes)) (VP (VBP react) (PP (IN with) (NP (NN NBS) (CC and) (NN water))) (PP (IN in) (NP (JJ halohydrin) (NN formation) (NN reaction)))) (. .)))
Alkenes react with NBS and water in halohydrin formation reaction.
(ROOT (S (NP (NNS Alkenes)) (VP (VBP are) (VP (VBN formed) (PP (IN from) (NP (NP (DT an) (NN alcohol)) (SBAR (WHNP (WDT that)) (S (VP (VBZ loses) (NP (NN water))))))))) (. .)))