196. Enantioselective synthesis of the Prelog-Djerassi lactonic acid via group-selective aldolization/desymmetrization of a meso dialdehyde with a chiral N-propionylsultam
     Oppolzer, W.; Walther, E.; Pérez Balado, C.; De Brabander, J.
     Tetrahedron Lett. 1997, 38, 809-812

The group-selective aldolization/desymmetrization of meso dialdehyde 5 with a borylenolate derived from N-propionylbornanesultament-2 yields very efficiently lactols 6with simultaneous generation of four stereogenic centers. Oxidation (6 → 7) followed by saponification of the sultam moiety (7 → 4) provided the Prelog-Djerassi lactonic acid 4 in a three step sequence in 61–71% overall yield.

DOI : 10.1016/S0040-4039(96)02408-2 

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