Thermodecarbonylation of α-Substituted Cycloalkanones: A Convenient One-Carbon Ring Contraction Method.

Steroidal cyclobutanones, III. The Synth

Steroidal cyclobutanones, III. The Synthesis and Stereochemistry of 3-Spiro-5α-cholestane Derivatives with Three-, Four-, and Five-membered Carbon Rings—A DoubleCine Substitution in Spiro-α,α-dichlorocyclobutan-3-ones

✍ Paryzek, Zdzislaw ;Błaszczyk, Krzysztof 📂 Article 📅 1993 🏛 John Wiley and Sons 🌐 English ⚖ 594 KB

## Abstract Diastereomeric [(3__S__)‐5α]‐ and [(3__R__)‐5α]‐2′,2′‐dichlorospiro‐[cholestane‐3,1′‐cyclobutan]‐3′‐ones (1 and 2), prepared by cycloaddition reaction of dichloroketene with 3‐methylene‐5α‐cholestane, served as starting material for the synthesis of the related spirane derivatives. Thus