Addition of RMgX and BrMg (CH2) nMgBr reagents to alkenylcatecholborane followed by iodine inducedrearrangement and oxidation provided Z-olefins and Z-olefinic alcohols in moderate to good yields. This procedure is advantageous over the previous methods of synthesis of Z-olefins from alkenylboranes since the alkyl groups which are not available through hydroborations can be also utilized.