Then, migratory insertion across the isopropenyl group would form alkyl palladium species III. β-hydride elimination is impossible due to the α-quaternary carbon center, and so this intermediate could be intercepted by a boron nucleophile (derived from B2Pin2 and KOAc) to deliver IV. Final reductive elimination would then deliver decalin V with a handle for further oxidation installed at C28. A key consideration in this reaction was the newly formed stereocenter at C4. While we had no concrete strategy to influence this stereocenter a priori, we anticipated that we could control stereoselectivity if we modified substrate I or selected an appropriate ligand. Initial experiments revealed that the unprotected alcohol and ketone were not viable substrates (see Supporting Information), both delivering undesired products. However, gratifyingly, we found that TBS-ether 16 (available in 3 steps from (R)-carvone) was able to cleanly undergo the desired borylative Heck reaction. After workup and oxidation, we were delighted to see that decalin 17 was formed with excellent diastereoselectivity (11:1) as indicated by H NMR analysis of the crude reaction mixture. Flash column chromatography provided 17 in 79% isolated yield as a single detectable diastereomer ( 1 H NMR). Presumably, migratory insertion occurs in such a way that the palladium center is positioned away from the bulky protecting group thus forming the desired equatorially disposed alkyl palladium species III.