Stereospecific reactions Baeyer-Villiger oxidation

S)-(+)-carvone. The key steps were Baeyer-Villiger oxidation, Oppenhauer oxidation, Meerwein-Ponndorf-Verley reduction, a stereospecific Grignard addition, and an intramolecular Sn2 reaction. 

The easy condensation of aldehydes with 3-monosubstituted oxindoles has been further exploited by Ban and co-workers, who synthesized several 3-spirooxindole derivatives 48). The approach was used in the stereospecific synthesis of racemic iV-methylrhynchophyllane (Chart X). The Iraws-diethylcyclopentanone CVIIIa was subjected to Baeyer-Villiger oxidation to yield the threo lactone CIX, which was converted to the chloroaldehyde CXI, by successive reaction with phosphorus... 

Schemes 10.16 and 10.17 lead to intermediates in which the C-1, C-3, and C-5 substituents are all cis to one another. In Scheme 10.16 the cis relationship between the C-1 and C-3 groups is again established by the Baeyer-Villiger oxidation, which is carried out as the first step in the synthesis. In step C, the cis relationship of the oxygen function at C-5 is established. The iodolactonization is a stereospecific anti addition, and the formation of cis-fused five-membered rings is preferred to the trans ring fusion. The other steps represent reactions that have been discussed previously.

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