Allylation reaction is one of the most important process in organic synthesis due to the synthetic flexibility of allylic systems. Described herein are the new methods to control regio-and stereochemistry of allylic compounds for efficient synthesis of acyclic terpenes. (1) Remarkable SN2'-, (E) -, and antiselectivities are observed in the coupling reaction between Grignard reagents and allylic phosphates in the presence of a copper (I) salt. (2) Stereochemically homogeneous mono-and di-substituted allylmetals can be directly prepared from the corresponding allylic halides and reactive metals at low temperature. (3) Allylic barium reagent reacts with a variety of carbonyl compounds to produce the homoallylic alcohol with remarkably high α -selectivity with retention of stereochemistry of the starting halides.