A short asymmetric synthesis of methyl 2-((1S,3R)-3-((tert-butyldiphenylsilyl)oxy)cyclopentyl)acetate from norbornene
2020
Huang, Buwen | Elleraas, Jeff | Ewanicki, Jason | Sutton, Scott C.
Methyl 2-((1S,3R)-3-((tert-butyldiphenylsilyl)oxy)cyclopentyl)acetate has been synthesized from norbornene using Hayashi’s (S)-MOP Pd-catalyzed asymmetric hydrosilation. On a 1 mol scale, asymmetric hydrosilation of norbornene afforded an 84:16 exo- to endo-norborneol mixture but with exclusive 1R,4S-stereochemistry at the bridgehead carbons. The norborneol mixture was converted to an optically pure chiral bicyclic lactone via a high-yielding tandem oxidation/Baeyer-Villiger reaction. Acid-promoted ring-opening of the lactone followed by immediate silyl protection afforded the chiral cis-1,3-cyclopentane intermediate in five steps with an overall yield of 41%.
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