8.10- Dodecadien

Using enantiomerically pure 4-hydroxy-2-alkynoate and 1,11-dodecadiene with CpRu(cod)Cl as catalyst, this reaction type was used in the synthesis of the acetogenin (+)-ancepsenolide, a bisbutenolide with a 12-carbon chain linking both lactone units "4. The primary addition step of this conversion represents an example of a ruthenium-catalyzed Alder-ene reaction (vide infra). Other examples of this type have been reported123. 

Dienes. Addition of alkenes to alkynes (ene-type reaction) is readily promoted by the Ru complex. Branched products are favored, and functional groups in the substrates are tolerated. Internal alkynes also undergo this addition. The 2 1 adduct from 1,11-dodecadiene and ethyl 4-hydroxypent-2-ynoate is a precursor of ancepsenolide. ... 

Dimethyloctyl)-2,6,10-trimethyl-1,11-dodecadiene, D-10283 1,16-Pentacosadiene, P-30028 7,11-Pentacosadiene, P-30029 2,6,10,14-Tetramethyl-7-(3-methyl-4-pentenyl)-5-pentadecene, T-20107... 

Brown and coworkers [ 13] have conducted exhaustive studies of the hydrobo-ration of a,o)-dienes 1,3-butadiene, 1,4-pentadiene, 1,5-hexadiene, 1,7-heptadi-ene, 1,8-octadiene, 1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, and 1,13-tetradecadiene with 2 molar equiv of 9-BBN, followed by the redistribution of the resulting dumbbell-shaped trialkylboranes with 1 molar equiv of borane-di-methylsulfide complex (BMS). 

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