Indole propionic acid inducers

Dixneuf, Bruneau and coworkers have reported an interesting reduction of the unsaturated acyl oxazolidinone (2.90). The reduction works with high yield and asymmetric induction, and the product (2.91) is effectively propionic acid with a chiral auxiliary attached. The chiral auxiliary was then used to induce asymmetry in a subsequent step. 2,3-Substituted N-Boc indoles imdergo hydrogenation to... 

In 1981, Wierenga first introduced a modification of Gassman oxindole synthesis for the synthesis of indole derivative 34, part of the left-hand segment of the antitumor agent CC-1065. In accordance to that, addition of derivative 30 in a equimolar amount of the hindered base, [1,8-bis(dimethylamino)naphthylene (R3N), to the chloride complex of ethyl-a-(mercaptomethyl)propionate 31, followed by a triethylamine catalyzed Sommelet-Hauser rearrangement and an acid-induced cyclization gave oxindole 32. Treatment of 32 with excess BH3 SMei at room temperature afforded 33 in 95% yield. 

---