Synthesis of a cis-5-Cyclodecenone and cis-Fused Hydronaphthalenols Through Control of the Stereochemistry of the Oxy-Cope Rearrangement with the Tri-n-propylsilyl Substituent.

Abstract In the course of preparing a trimethylsilyl substituted 5-cyclodecenone through anionic oxy-Cope rearrangement of a trans -1,2-divinylcyclohexanol, it was discovered that the silyl substituent in the divinylcyclohexanol is positioned so that it destabilizes [3,3]-sigmatropic rearrangement through the normally observed chair-like transition state. In the case of the tri- n -propylsilyl derivative, oxy-Cope rearrangement was observed to take place exclusively through the boat-like transition state to give ( E )-5-(tri- n -propylsilyl)-5-cyclodecenone with the cis double bond with respect to the ring. Acid-induced transannular cyclization of the E isomer led to 1,6-cyclization and generation of the cis-fused hydronaphthalenol.