195. Asymmetric synthesis of (-)-denticulatins A and B via group-selective aldolization of a meso dialdehyde with a chiral N-propionylsultam
     Oppolzer, W.; de Brabander, J.; Walther, E.; Bernardinelli, G.
     Tetrahedron Lett. 1995, 36, 4413-4416

Aldolization of meso dialdehyde 3 with a borylenolate obtained from chiral N-propionylsultam 4 yields efficiently lactols 5 with simultaneous generation of five stereogenic centers.Dithioketalization/O-desilylation of 5 affords acyclic diol 9 which is converted into the marine polypropionates 1a and 1bvia the asymmetric alkylation of N-propionyltoluenesultam 11 and the aldol coupling 10 + 15 → 16.

DOI : 10.1016/0040-4039(95)00787-D 

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