The stereochemistry and regiochemistry of the dehydration of  hexacarbonyl-μ-[η-(3RS,5S)-(+)-3,5-dimethyl-1-heptyn-3-ol]dicobalt  (Co-Co) and hexacarbonyl-μ-[η-(4RS,6S)-(+)-4,6-dimethyl-7-octyn-4-ol]  dicobalt (Co-Co) with diethyl ether-boron trifluoride  complex, trifluoroacetic acid or phosphorus(V) oxide have been investigated. The  distribution of the isomeric products [(E)-enynes 41-86%, (Z)-enynes  9-59%, enynes with exomethylene group 0-9%] is dependent on the substrate  structures as well as the nature of dehydrating agent. By acid-catalyzed  hydration of the corresponding enynes enantiomerically pure  (E,S)-(+)- 4,6-dimethyl-4-octen-3-one (manicone) and  (E,S)-(+)-3,5-dimethyl-3- hepten-2-one (normanicone) have been synthesized.
                                    六羰基-δ-[δ--(3RS,5S)-(+)-3,5-二甲基-
1-庚炔-3-醇]二
钴(Co-Co)和六羰基-δ-[δ--(4RS、6S)-(+)-4,6-二甲基-7-辛炔-4-醇] 二
钴(Co-Co)与二
乙醚-
三氟化硼络合物、
三氟乙酸或氧化
磷(V)的反应进行了研究。异构产物[(E)-烯炔 41-86%、(Z)-烯炔 9-59%、带外亚甲基的烯炔 0-9%]的分布取决于底物结构和脱
水剂的性质。通过酸催化相应烯炔的
水合作用,合成了对映体纯度为 (E,S)-(+)- 4,6 二甲基-4-
辛烯-3-酮(马尼酮)和 (E,S)-(+)-3,5 二甲基-
3-庚烯-2-酮(诺马尼酮)。