Scope and facial selectivity of the Prins-pinacol synthesis of attached rings

J Org Chem. 2006 Feb 17;71(4):1581-7. doi: 10.1021/jo0522862.

Abstract

Using a B-alkyl Suzuki cross-coupling as a key step, a concise and stereocontrolled synthesis of five- to eight-membered triisopropylsiloxy ethers having (2Z)-(6,6-dimethoxyhexylidene) or (2Z)-(5,5-dimethoxypentylidene) side chains was developed. Prins-pinacol reactions of these precursors promoted by SnCl4 provide bicyclic products in which 5-, 6-, or 7-membered rings are joined by a C-C single bond. Synthetically challenging attached ring systems in which both rings are chiral can be prepared in this fashion with high stereo- and enantioselectivity. Stabilizing through-space electrostatic interactions between the alpha-alkoxycarbenium ion and an axially positioned oxygen substituent are believed to play a significant role in organizing the transition structure of the Prins cyclization.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cross-Linking Reagents / chemistry
  • Cyclization
  • Ethers / chemistry
  • Heterocyclic Compounds, 2-Ring / chemical synthesis*
  • Static Electricity
  • Stereoisomerism

Substances

  • Cross-Linking Reagents
  • Ethers
  • Heterocyclic Compounds, 2-Ring